Answer:
Option (2)
Explanation:
Glossopteris were the fossilized trees whose leaves were tongue shaped, and were about 30 meters in height. This trees were dominant in the Permian and got extinct due to the Permian-Triassic mass extinction. The fossils of this glossopteris has been found in all the continents of southern hemisphere. This provided a good evidence supporting the continental drift theory.
It was observed that the continents were all once together and now have separated and these continents are now moving at different place in different direction due to the convection current that forms in the mantle. This supports the plate tectonic theory.
Hence, the correct answer is option (2).
Which of the following is a basic structural component of the most common mineral group?
metallic bonds
a water molecule
a carbonate ion
a sulfate ion
a silicon-oxygen tetrahedro
Answer:
Silicate-Oxygen tetrahedro
Explanation:
Silicate-Oxygen tetrahedro are the most abundant and basic structure of common minerals.
These are silicate minerals which formed to silicate rock forming mineral. These constitute about 90% of earth crust. Silica SiO2 consider as most common mineral on the surface of earth also known as Quartz. The the most andundant element in the earth crust is oxygen, mainly found in combine form.
Question 11(Multiple Choice Worth 3 points) If solidification ages at the Mid-Atlantic Ridge are around 10,000 years old, what does this tell you about the Mid-Atlantic Ridge? The Mid-Atlantic Ridge began to produce oceanic crust 10,000 years ago. The youngest rocks in the Mid-Atlantic Ridge solidified 10,000 years ago. The Mid-Atlantic Ridge ceased producing oceanic crust 10,000 years ago. The rocks at the Mid-Atlantic Ridge recorded the magnetic fields 10,000 years ago. The rocks adjacent to the Mid-Atlantic Ridge are older than those further away from the ridge.
Answer:
Option (2)
Explanation:
The mid-oceanic ridge is the region along which the sea floor spreading takes place. It forms a divergent plate boundary. Here, the magma forces to come out to the surface, by stretching and thinning the lithosphere. These magma as it comes out to the ocean floor along this mid-oceanic ridge, it immediately cools and form rocks that are basaltic in composition and lavas are formed. The Mid-Atlantic ridge is an example of mid-oceanic ridge.
According to the given condition, the solidification age at the Mid-Atlantic ridge is given. This indicates that the rocks that last crystallized 10,000 years ago at the Mid-Atlantic ridge are the youngest rocks.
Hence, the correct answer is option (2).
If you travel west through 10 degrees of longitude along the equator, the distance traveled will be very different from the distance traveled through 10 degrees of longitude at 60 degrees North latitude. Why?
When you travel θ degrees of longitud at a certain latitude, you are travelling along the arc of a circle. The radius R of that circle is decreases as you approach one of the poles: it is maximum at the equator, and zero at the pole.
The arc of circle is S = R*θ. At 60 degrees latitud North, R is less than at the equator.
A water quality standard recognized in British Columbia for Zn
in marine environments is 10 ?g/L. Convert this to (a) milligrams
per liter and (b) nanomoles per liter. Molecular weight of Zn:
63.38 g/mol.
Answer:
[tex](a)\ 10^4\ mg/L[/tex]
[tex](b)\ 10^{10}\ mg/L[/tex]
Explanation:
(a) As given in question,
concentration of zinc in atmosphere = 10 g/L
By converting g to mg,
1 g = 1000 mg
=> 10 g = 10 x 1000 mg
[tex]=\ 10^4\ mg[/tex]
Hence, the concentration of zinc in the environment in mg/L is [tex]10^4\ mg/L.[/tex]
(a) As given in question,
concentration of zinc in atmosphere = 10 g/L
By converting g to nano gm,
[tex]1\ g\ =\ 10^9\ nano\ gm[/tex]
[tex]=>\ 10\ g\ =\ 10\ \times\ 10^9\ nano\ gm[/tex]
[tex]=\ 10^{10}\ nano\ gm[/tex]
Hence, the concentration of zinc in the environment in nano gm/L is [tex]10^{10}\ nano\ gm/L.[/tex]
Question 18 Which moon in the table of moons should be the most rocky? Which one should be the most icy?
Answer:
Ganymede is the biggest and the most massive moon of the planet Jupiter. It has a metallic core. It moves in an orbital path around the planet Jupiter and orbits every 6-7 days. Half of the moon is comprised of silicate rocky materials and half of it is made up of water ice. Out of all the moons, Ganymede has the highest rock composition.
Europa is one of the moons of Jupiter. It is even smaller than the earth's natural satellite (moon). The core of this moon is made up of iron and nickel, along with some silicate materials but they are extremely in a lesser amount in comparison to the earth's core. Europa's surface is comprised of ice and water is present in a significant amount below the surface.
explain effects of different fire regimes on total soil carbon and organic carbon and dissolved organic carbon.
Answer:
Explanation as below.
Explanation:
As soil is composed of organic matter that includes the carbon contents, the fire regime leaves a bad impact on the soil nutrients such as bleaching of nutrients and minerals, also the crop fires are a common type of regime followed in various vegetation clearance practices. The dissolved soil organic content includes acids, fats, sugars, proteins, enzymes, and hydrocarbon fuels. As all organic matter consists of carbon , inorganic carbon is extracted from ores and minerals. DOC is abundant in minerals and freshwater. Also, forest fire on shrublands kills bacteria and fungi in soil surfaces. Loss of soil matter and increased bulk density can decrease the water keeping the holding capacity of the soil. Surface erosion by wind or gravity can also increase when ground cover.When considering centrifugal force, which of the below scenarios has a sign coefficient of 1?
A .Southern Hemisphere Low pressure
B. Northern Hemisphere Low pressure
C. Northern Hemisphere High pressure
D. Western Hemisphere Low pressure
Answer:
A .Southern Hemisphere Low pressure
Explanation:
When considering centrifugal force, The southern Hemisphere Low pressure has sign coefficient of 1. The rotation of Earth causes the centrifugal acceleration. The magnitude of centrifugal force is given by mv^2r.
Where m is mass of rotating body , v is the linear velocity and r is the radius of rotation. The centrifugal force always works outside the center of the circular motion.
a common misconception about earth's mantle is that it is a
thick layer of molten rock. Explain, in your own words, why Earth's
mantle is actually solid under normal conditions.
Answer:
Lava or magma is considered to be in molten state while the earth's mantle is layer of rocks that changes its state
Explanation:
Earth's mantle is composed of solid rocks that exist in a liquid form, the upper layer is that of the Asthenosphere and the layer of the mantle is further divided into upper, lower and transitory layers. Being the massive and most widely occurring layer covering the planet. It has a layer of silicate between the crust and outer core. It is approximately 1600 km thick. The upper mantle contributes to the tectonic activity as the rocks in this layer are malleable. There are 15 major and minor slabs above the layer and lava i.e the molten rock is burned inside the magma at grater depths and as there exists water in the mantel the transition zone is evident from the upper and lower exchange of minerals.What are some of the environmental issues in Mexico that could contribute to poor health and economic problems? Can you explain ways you'd solve those issues also?
Answer and Explanation:
Some of the major factors for the environmental issues in mexico are:
1. Contamination of the environmental resources and the degradation of the level of oxygen as a result of the cutting down of forests and natural habitats loss.
2. Chemical contamination because of deceptive release of the material leaving the industrial facilities and exploitative dumping.
3. Increment in the population growth resulting from migration of people from other counties, lower Infant Mortality rates, better life expectancy of the residents as a result of good nutritional intake.
All these factors results in the increase in the basic needs of the people thus requiring more land and hence clearing of trees and land area.
Mexico should build the quantity of biosphere reserves and should center ecotourism for protection of its tendency.
Alongside this, they have to center populace control measures to be aware of population development. They should likewise turn out to be a piece of worldwide ecological projects that concentrates on the factors to safeguard our environment and should pay attention to the IPCC rules. They should join Convention on International Trade in Endangered Species (CITES) likewise and should stay up with the latest elements of the world. Aside from this, they ought to likewise do legitimate Environmental Impact Assessment before beginning of a formative undertaking.25. The only country listed below that does not have a Mediterranean Climate region is: a. USA b. Chile c. France d. Argentina e. Italy 26. Diffusion by migration wherein innovations are carried by a relocating population is called diffusion. a. hierarchical b. contagious c. relocation d. expansion 27. Which of these countries does not have a coastline on the Atlantic Ocean? a. Panama b. Costa Rica c. Belize d. El Salvador 28. The country listed below that has the largest population is: a. Norway b. Greece c. Portugal d. Italye. Czech Republic 29. Scandinavia includes the countries of a. Norway, Sweden, and Denmark Iceland, and Estonia b. Finland, 30. Belgium is officially bi-lingual, with the two main languages, and German spoken by about 7% of the population. a. French and Dutch b. English and Danish c. Spanish and Italian
Answer:
25. c. France; 26. c Relocation; 27. d. El Salvador; 28. d. Italy; 29. b. Finland; 30. a. French and Dutch
Explanation:
France is the only country from the list that does not have a Mediterranean Climate region.
In terms of diffusion by migration, hierarchical focuses on spreading from larger areas to small ones but strongly influenced by elites. Contagious focuses on spreading of innovation from person-to-person. Relocation focuses on migration which leaves behind its origin. Expansion focuses on spreading to outer areas while remaining strong in its source area. Thus, the problem refers to relocation.
El Salvador is the only country from the list that does not have a coastline on the Atlantic Ocean.
Of the countries listed in the problem, Italy has the largest population (60 million people).
Scandinavia includes the countries of Norway, Sweden, Denmark, Iceland and Finland. Estonia is not one of them.
Belgium is officially bilingual. They speak French and Dutch.
Geology- a unifying theory gives us one broad explanation for a number of phenomena where, previously, we needed separate explanations. How does the plate Tectonics theory serve as a unifying theory?
Answer:
The plate tectonic theory is considered to be a unifying theory. According to this theory, the earth's crust is made up of numerous small and large pieces of lithospheric plates. These lithospheric plates are of 2 types, namely the continental crust and the oceanic crust. These plates continuously flows over the less dense layer of the asthenosphere due to the convection current that generates in the mantle. This current initiates because of the heat radiated from the interior of the earth. The main mechanism for the plate motion was determined later and this theory proved the continental drift theory that was not able to explain the main mechanism for the drifting of the plates.
This theory describes how the plates on earth were once all together and how they were separated with time, causing various changes and formed various types of landforms, shaping the earth's surface.
One of the reasons ______ environments tend to be warmer than _______ is that _______ surfaces tend to be covered with buildings and roads which have low albedo
Question 60 options:
urban, rural, urban
continental, rural, continental
rural, urban, rural
maritime, rural, urban
The correct answer is A. urban, rural, urban
Explanation:
In general terms, the temperature is related by multiple factors that include the altitude, latitude, weather, among others. Besides this, it has been found the temperature of the same geographical zone can vary depending on whether the zone is urban or rural. In this way, rural zones can be 1° to 3° grades hotter (even up to 7° grades) that urban zones, this can be explained as in urban zones surfaces are covered by roads, buildings or similar instead of trees, grass or lakes, and these type of artificial structures tend to absorb heat but not reflected which refers to the albedo. Thus, urban environments tend to be warmer than rural because urban surfaces have a low albedo.
Answer:
The correct answer is A. urban, rural, urban
Explanation:
In general terms, the temperature is related by multiple factors that include the altitude, latitude, weather, among others. Besides this, it has been found the temperature of the same geographical zone can vary depending on whether the zone is urban or rural. In this way, rural zones can be 1° to 3° grades hotter (even up to 7° grades) that urban zones, this can be explained as in urban zones surfaces are covered by roads, buildings or similar instead of trees, grass or lakes, and these type of artificial structures tend to absorb heat but not reflected which refers to the albedo. Thus, urban environments tend to be warmer than rural because urban surfaces have a low albedo.
Explanation:
The climatic shift that was a major contributing factor to the collapse of the Viking colonies is known as the ________ ____ _____
Answer:
Greenland Norse collapse
Explanation:
The southern Greenland Vikings numbering 5000 at their peak never gave up their old way of lifestyle and did not adopt that of the Northern Inuits who arrived a century later after them. The study suspects that the climate factors became dominant and they were destroyed by the shifting nature of mother earth hence they starved to death and could not adapt to the present change in weather patterns this society collapsed. Some theories say soil grazing and over-exploitation of land lead to the effect of black deaths and the creation of ice age. It indicated that the number of fertile women dropped and thus population could not sustain itself.1) Joints differ from faults primarily
with respect to the types of deformation that form them
with respect to strength of the rocks
whether displacement has occurred
the amount of weathering to which they are prone
2) The law of cross-cutting relationships pertains to the age relationships in a sequence of sedimentary layers.
True
False
3) Neutrons add charge, but not mass, to an atom.
True
False
Answer:
1- Option (C)
2- TRUE
3- FALSE
Explanation:
Joints are the type of fracture that splits the rock into two parts thereby the blocks move away from one another. They are formed due to the tensional force. Whereas, the fault, in simple terms is defined as the cracks or fractures present in the crust of the earth. They are formed by both tensional as well as compressional forces. They differ from one another in terms of displacement. In a fault, the relative displacement between the blocks is more than in the case of joints.
According to the law of cross-cutting relationships, geological features such as faults, igneous intrusions, that cuts across the sedimentary layers on earth are younger than those sedimentary rocks.
A neutron is a neutral particle as it does not carry any kind of electric charge. So, the addition or elimination of neutron from the nucleus does not affect the electric charge of the nucleus. But it can cause changes in the mass within the nucleus. Isotopes originate due to the addition or removal of neutrons from a nucleus.
Hence, the correct answers are given above.
4. What problem has precession caused for many schools of astrology?
Answer:
In Astrology, hub precession is a gravity-instigated, slow and constant change in the direction of a cosmic body's rotational pivot.
Explanation:
Specifically, it alludes to the steady move in the direction of Earth's pivot of revolution, which, similar to a wobbling top.
The expression precession regularly alludes just to this biggest mainstream movement; different changes in the arrangement of Earth's pivot - nutation and polar movement - are a lot littler in greatness.
The majority of glaciers on planet earth are in either or regions
Answer:
Majority are on continental regions
Explanation:
Moat of glacial ice and ice caps are found in polar regions of the earth as they are home to permanent frosting and valley glaciers in the interior of the continents like in Asia, Africa, and other countries are not so much developed as they tend to stagnate or be limited due to the landmasses characteristics. Greenland and Antarctic glaciers together combine and makeup 99% of the freshwater reserves and ice on earth. As they were spread over a large surface of the earth the Antarctic glacier covers 25,400,000 km on the surface. These glaciers produce a thick mass of ice as compared to the valley glaciers which are unstable and have braided streams. Being characterized by retreating glaciers, and having an average mass of 4%.question 55:
As the altitude increases, the temperature of the atmosphere decreases in this layer of the atmosphere.
I. Troposphere
II. Stratosphere
III. Mesosphere
IV. Thermosphere
Question 55 options:
I and III
II and III
I and II
II and IV
Answer:
Option (1)
Explanation:
The atmosphere plays an important role in controlling the earth's climate. This atmosphere is comprised of different layers. They are as follows-
(a) Troposphere- This layer extends up to a height of about 10 km from the ground surface. In this layer, the temperature and altitude are inversely proportional to one another. This decrease in the temperature with increasing height is known as the Lapse rate and is 6.5 degree C/km.
(b) Stratosphere- This layer is present above the troposphere. It extends from about 10 to 50 km above the surface. Here, the temperature increases with height. It is because of the presence of ozone in this layer that warms the layer.
(c) Mesosphere- This layer is above the stratosphere and below the thermosphere. It extends vertically from about 50 to 80 km above the ground surface. The temperature again decreases with height in this layer.
(d) Thermosphere- This layer forms the outermost layer. Here, the temperature and height are directly proportional to each other.
Thus, the temperature decreases with altitude in the layers, namely the troposphere and the mesosphere.
Hence, the correct answer is option (1).
(This is for US Music Social & Political Impact) Need a paragraph please
What factors made the study of traditional Native American music difficult for the ethnomusicologists who were interested in researching it?
Answer and Explanation:
Native american don't have any melodic hypothesis to give data with respect to their melodic traditions.Their music is fundamentally vocal and non-instrumental this makes measure of data present in open circle even less.Also local american culture has been hurt and devastated by non-locals, as America was settled essentially from European and African pilgrims
So generally we rely upon records of European Scholars with respect to the history and culture of local Americans.These European researchers had distinctive taste of music, so records of these researchers are misshaped. That is the reason it is hard for the ethnomusicologists to examine the local american music.
A long time ago, sailors recognized the lack of wind in the ITCZ and dubbed the region the"doldrums". What other situations can you think of where sailors made discoveries that are now justified by modern science?
Answer:
"Doldrums" also called as he Horse latitude.
Explanation:
The equator is generally considered as the region of calm later on it was called the ITCZ. Now its called the doldrums as the belt of the equator which houses the Hadley cells. This is marked by the zero degrees latitude and this zone is the zone of mixing of atmospheric trade winds, earlier times sailors who came at this place along with their ships and horses but had to experience long-lasting high velocity prevailing winds at an altitude of 30, 40, 50, 60 degrees. So they named these winds on these altitudes as the forties, screaming sixties filtering fifties. These winds were so strong that their ships used to get drowned with horses in these latitudes. These were the discoveries made by the sailors.The symbolic nature of culture:
a-Facilitates cross-cultural communication, because all cultures use the same (or very similar) symbols to mean the same things.
b-Can create considerable misunderstanding between people from different cultures.
c-Is now known to be not as significant as anthropologists once believed.
d-Is easily discernable from the archaeological record.
Answer:
B
Explanation:
The symbolic nature of culture:
b-Can create considerable misunderstanding between people from different cultures.
Symbols can be a basis representation of different culture and it can be in the form of an object, word, color,sign,gesture or action. People can get considerable misunderstanding by different cultural symbolism because many symbols, though similar in appearance, can mean drastically different things.
1.Pointing with Thumb
Malaysia - Respectful
In Other culture- Meaningless
2.Calling with index finger
United States -Respectful
In Other culture -Offensive.
3.Thumb up
Iran-Obscene
in Others cultures- Goodluck
By these examples we conclude that symbols Can create considerable misunderstanding between people from different cultures.
Select all of the correct answers: AU is:
varies dependant upon the time of year
used primary to measure things within the solar system
a measurement of distance
the distance from the center of the Sun to the center of the Earth
is the distance from the Earth to the Moon
Answer:
used primary to measure things within the solar system
a measurement of distance
the distance from the center of the Sun to the center of the Earth
Explanation:
Astronomical unit ( AU )
The value of 1 astronomical unit ( AU ) = 92,955,807 miles or 149,597,871 km , which is equivalent to about 150 million kilometres . it is the average distance between the sun and the earth .
It is used as a measurement unit , for the solar system , the AU , measures the distance , hence its units are miles , km etc .
Final answer:
An Astronomical Unit, abbreviated as AU, is the average distance from Earth to the Sun, used primarily to measure distances within the solar system, and is about 150 million kilometers. (First and fourth options)
Explanation:
An Astronomical Unit (AU) is the unit of length defined as the average distance between Earth and the Sun. This distance is about 150 million kilometers (93 million miles) or precisely 149,597,870.7 kilometers. The AU is commonly used to measure distances within the solar system, making it a fundamental concept in astronomy.
The statements regarding the AU as a measurement that varies depending upon the time of year or as being the distance from the Earth to the Moon are incorrect. While the Earth-Sun distance does vary over the course of a year due to Earth's elliptical orbit, the AU represents the average of these distances.
Moreover, the distance from Earth to the Moon is measured in Earth-Moon distances, known as lunar distances, not in AUs.
What are the principal sedimentary rocks? What is the genesis (origin) of each sedimentary rock type?
Answer:
The sedimentary rocks are those that are formed due to the compaction and lithification of sediments. Some of the examples are shale, mudstone, sandstone and limestone.
This sedimentary rocks are divided into 2 principle types. They are as follows-
(1) Clastic sedimentary rocks- This type of rocks are formed when the rock particles are weathered physically from the terrestrial rocks (source area) and are transported from one place to another by means of wind, water and ice. These rocks are named depending on the size of the sediment particles. Conglomerates and sandstone are examples of clastic sedimentary rocks.
(2) Chemical (Carbonate) sedimentary rocks- This type of sedimentary rocks are formed due to the precipitation of certain minerals from water. Due to this precipitation, the water releases the dissolved minerals. Some of them are also comprised of carbonate minerals that precipitates when reacts with water. In addition to that, some fragments of marine fossils are also found to be accumulated in this type of rocks. For example, rock salt, halite, dolomite, chert and limestone.
Please, answer in complete sentences.
1. How do we know that the Earth is approximately spherical? What is the Earth’s true shape?
2. Describe the effects of Earth’s rotation on its axis.
3. Briefly describe the positive and negative aspects of the map projections listed below.
Mercator Projection:
Goode Projection:
Polar Projection:
4. Explain the global timekeeping system. Mention standard time, standard meridians, and time zones in your answer.
Answer:
Answers given below.
Explanation:
Earth is not a perfect sphere but a geoid or elliptical, some claim that distance of the sun and rapid spinning of the earth on its axis from the equator to the poles is narrowed downwards. Effects of this rotational motion influence the seasons and oceanic currents and wind patterns. The angle of inclination that the sun makes with the earth is also affected due to the tilt and hence there is uneven heating of the earth at various altitudes. As the aspect of positive map projection is that it helps in navigation such as that of the Mercators projection but it distorts the upper spheres of earth and the Googe projection is an equal-area projection used in multiple worldwide interruptions also called as homolographic projection. Guillaume Postel created the polar projection used it represents the north polar regions. Its drawbacks are that the southern hemispheres of the map are distorted heavily. The time zones for the northern hemisphere and southern hemispheres are divided from the UTC points in Greenwich England.QUESTION 2 OF 3
Which river was completely within the boundaries of the Persian Empire, Alexander’s conquests, and Mauryan Empire?
A. Ganges
B. Krishna
C. Brahmaputra
D. Indus
Answer:
d. The Indus river was completely within the boundaries of the Persian Empire, Alexander's conquests, and Mauryan Empire
Explanation:
The Indus river is located in what it is Pakistan these days. It is the only river that was completely within the boundaries of the Persian Empire which include parts of current Pakistan, Alexander's conquests which included territories from Macedonia until parts of India, and also Mauryan Empire that included parts of current Pakistan up to some parts of current Bangladesh. The river Ganes, Krishna and Brahmaputra were part of the Mauryan Empire however, they are not included in the Persian Empire or of Alexander's conquests.
What are the advantages and/or disadvantages of using GE
crops?
Answer:
Various advantages and disadvantages are given as under
Explanation:
Pros:
As Genetically modified crops are genetically disease resistant they have been proven safe through testing and use. They increase the nutrient contents and reduce the worldwide hunger levels, also lower prices of food. They lead to environmental benefits such as reduced pesticides use and lower carbon emissionsCons:
They have not been proven safe for human consumption through trials. Genetically modified crops can lead to the development of various food allergies in the body. They are water-intensive Increased use of toxic herbicides and pesticides damages soil fertility.What is geology? Why is it important that everyone have a basic understanding of geology, even if they aren't going to become geologists?
Answer:
Geology refers to the study of the earth's physical and chemical processes, how they occurs and what are its effects. It explains how the earth has formed over millions of years. It also describes the internal structure of the earth and the study of the rocks and its minerals. It is a vast subject that is related to physics, chemistry, and biology.
The basic concept of geology must be known to all because earth undergoes various changes with time. Some of the events that occur at different places on earth are earthquakes, tsunamis, floods, hurricanes and so on and the conditions under which these processes occur must be known to all. It provides an idea of how to be away from such destructive processes.
Thus, geology is a very important subject and one must have basic knowledge about it.
Q2: The present-day topography of Arizona formed over a time interval that encompasses less than ____ percent of the entire geologic history of the state.
Answer:
Sixty percent
Explanation:
As Arizona is the sixth largest state in North America ranked after Mexico, the state has 113,998 square miles 295,000 km square. The landscape is rich with cactus plants. Located in Arizona is the great canyon a steep-sided gorge carved by the colorado river. The climate is primarily desert with mild winters and extremely hot summers. The southwest of Arizona has an abundance of mountains and plateaus besides this the state also has aridity of 27%. Colorado plateau covers 5,000 to 8,000 feet. In Arizona lies a transitional zone of Mogollon Rim, a cliff and a dramatic escarpment this terrane receives heavy rainfall due to the mountain ranges and temperature by latitudes. Arizona is home to four deserts like the Sonoran desert, Mojave desert, Painted desert, Chihuahuan desert.Answer these questions: (3 to 8 paragraphs for each question)
Assignment Instructions: Prepare a 4-10-page essay answering the questions below
6. What is dark energy? How much of the universe is thought to be dark energy?
Answer:
The dark energy is one of the primary composition of the universe, which is not visible and are mysterious. as a very little is known about this energy. This dark energy makes up nearly 68% of the universe. It is often considered as a property of space. The presence of dark energy can be detected as it affects the expansion of the universe. The universe started to form right after the big bang explosion and since then the space is expanding in all direction. With this, the dark energy present in the universe also is expanding at a considerably faster rate in association with the Cosmic Microwave Background (CMB) radiation. The measurements of the distance and their connection with the redshift provided an evidence that the universe has been expanding at a certain speed.
Which of the following is true about radiation?
Question 35 options:
Radiation is always harmful to human health
Electromagnetic waves are measured in terms of their wavelength and color
Visible lights is the only electromagnetic energy from the Sun
Radiation is electromagnetic energy that is transmitted in the form of waves.
Answer:
Option (4)
Explanation:
The radiation are defined as the energy that is liberated from atoms in the form of electromagnetic waves or minute particles of matter. For example, the radiations that are emitted from the sun in the form of light.
This radiations are mainly of 3 types. This includes-
(a) Alpha Radiation- These are the short ranged particles and are very heavy. This radiations cannot penetrate the human skins but they can cause harmful diseases.
(b) Beta Radiation- These are also the short-ranged particles but they lighter. This radiations can penetrate the human skin upto the depth where the new skins are created.
(c) Gamma Radiation- These are highly dangerous and are penetrable to the human skin. This type of radiations are often used for the medical purposes.
Thus, the correct answer is option (4).
Answer:
gffffffffffffffffffffffffffd
Explanation:
fffffffffffffffffff
Why does hardness increase with shorter distances between the metal and the oxygen?
a.
The metallic bonding is optimal when the distances between the metal and the oxygen are the smallest.
b.
The electrostatic forces are the strongest when the metal and oxygen are closest together, making the compound harder.
c.
The chemical repulsion is the greatest when the metal and oxygen are closest to each other, making the compound harder.
d.
The magnetic attraction is the strongest when the metal and oxygen are closest together, making the compound harder.
Answer: Option (A)
The metallic bonding is optimal when the distances between the metal and the oxygen are the smallest.
Explanation:
Hardness increases with respect to shorter distances between the metal and the oxygen compounds, the reason for the increase in hardness is due to metallic bonding (electrostatic force between electrons and positive ions) which is optimal between them.
As the distance decreases, hardness increases and for increasing distances hardness decreases. So when the molecular weight is large, it has smaller valence or less charge on the metal which makes the bond weaker and less hard.