1. According to the periodic law, both chemical and physical elements and their properties are periodic functions of their atomic numbers, thus recurring in a predictable periodical pattern
2. Mendeleev knew that some certain elements existed, he expected that in the future, the gaps would be filled because at the time, they had not been discovered yet.
3. The properties of metalloids are boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te), polonium (Po) and astatine (At). They are found between metals and non-metals on the periodic table. They appear in a stairstep-like pattern.
Answer: Mix of answers below
Explanation:
The Periodic law is a physics law that determines on how many groups will the elements be split into, taking into acount their atomic numbers. According to them, an order will be listed. We'll be able to find regular intervals for a determined number of elements that a share a similarity on its properties.Mendeleev left gaps in his early periodic table because even though he was sure there was more elements to exist, those hadn't been officially discovered yet. Metalloids main properties are:Density: this is a concepts used to describe the relationship between mass and volume.Electric conductivity: metalloids are fairly good electricity conductors. However, since we have a distintion between metalloids and actual metals, these last ones are far more better at this task.How can people obtain groundwater from an aquifer
What property is both physical and extensive?
A.
density
B.
volume
C.
sodium metal reacting in water
D.
boiling point
Help!! Chemistry!! Please!!
In the oxidation-reduction reaction H2O + 2MnO2 + Zn → Mn2O3 + Zn(OH)2, the half-reaction of the zinc is?
a. Zn(OH)2 → Zn + 2e-
b. Zn(OH)2 → Zn + 2OH-
c. Zn + 2OH- → Zn(OH)2 + 2e-
d. Zn + 2OH- + 2e- → Zn(OH)2
C is the correct answer choice.
Answer:
D
Explanation:
2MnO2 + H2O => Mn2O3 + 2OH is the correct balanced equation. All others are missing or have incorrect coefficients.
Why do some transition metals have multiple oxidation states?
Answer: The reason is the number of degenerate electrons.
Explanation: Transition elements are the only elements in the periodic table which are capable of showing variable oxidation states.
Tranistion elements has 'd orbitals' as their penultimate shells which are not perfectly shielded by the inner orbitals. And these d orbitals can occupy 10 electrons in their 5 orbitals.
Thus they can easily lose electrons as the energy of the electrons are the similar or better say that they are degenerate.
Why are mixtures such as sugar and water not given chemical formula
No chemical bonding took place. The elements or compounds in the mixtures have no definite proportions.
Mixtures like sugar and water do not have a chemical formula because the substances in them retain their individual chemical identities and are not in a fixed ratio. Solutions of sugar in water are considered homogeneous mixtures and the sugar, sucrose or C12H22O11, is evenly distributed but does not chemically bond with water to form a new compound.
Explanation:Mixtures such as sugar and water are not assigned a chemical formula because they do not form a new chemical compound with a fixed ratio of components. In mixtures, each substance maintains its chemical identity and the components are not in a fixed ratio, meaning you can mix them in virtually any proportion. This is different from a compound, where the elements are chemically bonded and always present in a specific ratio.
Take, for example, a solution, which is a type of homogeneous mixture where one substance is dissolved in another. Sugar dissolved in water forms such a solution. When sugar (sucrose) dissolves in water, the molecules of sucrose, C12H22O11, become evenly distributed among the water molecules, but no new compound is formed. Hence, the solution is represented as C12H22O11 (aq), indicating that it is an aqueous solution of sugar, not a new compound warranting a unique chemical formula.
In contrast, a compound like table salt (NaCl) is made of a fixed ratio of sodium (Na) and chloride (Cl) ions chemically combined, resulting in properties different from those of the individual elements. Compounds can only be separated into their elemental components through chemical reactions, not by physical processes like filtering or distillation.
How is a pure substance different from a mixture? A. Pure substances cannot be seperated by physical means.B. A pure substance is heterogeneous.C. A mixture is made of ine substance.D. Mixtures cannot be seperated by physical means.
Pure substances cannot be seperated by physical means.
Using paper chromatography, how can you separate a homogeneous mixture into its component chemicals?
Paper chromatography is a tool frequently used in analytical chemistry to separate a homogeneous mixture into its components.
In paper chromatography the stationary phase is water which drenches the paper and the mobile phase is a mixture polar organic solvent and water. The various components of the homogeneous mixture is separated based on their relative solubility in either the mobile or stationary phase.
The prefix kilo- means a thousand. So a kilo-gram is a thousnd grams. 1kilogram=1,000 grams how many kilograms 1,830 grams?
Given data:
1 kilogram = 1,000 grams
How many kilograms 1,830 grams?
Solution:
1000 grams = 1 kilogram
1 gram = 1/1000 kilograms
1,830 grams = 1/1000 * 1830 = 1.830 kilogram
Hence 1,830 grams = 1.830 kilogram
Which of the following is not an example of a compound? A substance comprised of:
atoms of the same element
atoms of two different elements
positive particles of one element attracted to negative particles of a different element
positive particles of one element attracted to negative groups of atoms of other elements
Answer: atoms of the same element.
Justification:
There are two kinds of pure substances: elements and compounds.
Elements are pure substances consiituted by one kind of atoms. They cannot be divided into simpler substances either by physical or chemical means. This leads you to the answer of the question: atoms of the same element is not an example of compound, but of elements.
On the other hand, a compound is a chemical combination of two or more different atoms. The compounds can be splited into simpler substances (the elements) by chemical means.
Hence, second, third, and fourth choices are all examples of compound: they are pure substances of two or more kind of atoms.
How many orbitals are completely filled in an atom whose electron configuration is 1s^2 2s^2 2p^6 3s^1?
Im not sure if it is 3 or 5
The number of orbitals that are completely full is 5.
The reason you may have thought it was 3 is because you're confusing orbitals with subshells.
In this electron configuration, the sub shells are: 1s^2, 2s^2, 2p^6, 3s^1
So, we have four sub shells.
Each sub shell consists of a specific number of orbitals. s subshells have one orbital, p subshells have three orbitals, d subshells have five orbitals, and f subshells have seven orbitals. Knowing this, we can look back at the electron configuration we were given and determine how many orbitals are filled.
1s^2 has one orbital, 2s^2 has one orbital, 2p^6 has three orbitals, and 3s^1 has one orbital. The first three subshells are completely full, so a total of five orbitals are full.
The number of orbitals that are completely filled in an atom whose electronic configuration is 1s²2s²2p⁶3s¹ is 5
Electronic configuration can simply be defined as the arrangement of electrons around the nucleus of an atom.
The electrons in an atom are arranged in orbital. These orbitals includes: s-orbital, p-orbital, d-orbital and f-orbital
S-orbital has 1 subshell = maximum of 2 electrons
P-orbital has 3 subshells = maximum of 6 electons
D-orbital has 5 subshells = maximum of 10 electrons
F-orbital has 7 subshells = maximum of 14 electrons
With the above information in mind, we can determine the number of orbitals that are completely filled in the atom given in the question above. This can be obtained as follow:
Electronic configuration => 1s²2s²2p⁶3s¹
1st shell => 1s² = 1 subshell = 2 electrons (complete)
2nd shell => 2s²2p⁶ => 4 subshells = 2 + 6 = 8 electrons (complete)
3rd shell => 3s¹ => 1 subshellsubshells => 1 electron (incomplete)
From the above illustration, we can see clearly that only 5 orbitals are completely filled.
Thus, we can conclude that the number of orbitals that are completely filled in an atom whose electronic configuration is 1s²2s²2p⁶3s¹ is 5
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Which quantity is constant when working with boyles, charles, and gay lussacs law?
boyles law states that the volumes of a gas will decrease as pressure increases if the temperature remains constant.
charles law states that the volume of a gas will increase as temp increases if the pressure remains constant.
gay-lussacs law states that the pressure increases as temp increases if the volume remains constant.
moles has been the constant
Which statement best explains why calcium has a larger atomic radius than magnesium?
A.
Calcium has a stronger nuclear charge than magnesium.
B.
Calcium has electrons in more energy levels than magnesium.
C.
Calcium has more neutrons than magnesium.
D.
Calcium’s third energy level contains more electrons than magnesium’s.
Electron shielding effects reduces the effect of a full nuclear charge. As more of the core electrons are added, they begin to 'shield' the valence electrons from the increasingly positive nucleus. But this will allow the outer electrons to move farther away from the nucleus, hence increasing atomic size. The electron shielding effect is responsible for the increase in atomic size moving down groups.
B. Calcium has electrons in more energy levels than magnesium.
B. Calcium has electrons in more energy levels than magnesium.
Draw the major byproduct of the reaction (not the minor species discussed in q2b). At which stage did you remove it from your sample?
You need to do something like that your self so sorry can help.
How many liters of water vapor can be produced if 8.9 liters of methane gas (CH4) are combusted, if all measurements are taken at the same temperature and pressure? Show all of the work used to solve this problem. CH4 (g) + 2O2 (g) yields CO2 (g) + 2H2O (g)
The normal condition of the mole of a gas is 22.44L.
The volume of CH4 = 8.9L
To get the number of moles we get,
8.9 / 22.44 = 0.397 moles.
The ratio of CH4 : H2O = 1: 2
The mole of water is 0.379 × 2 = 0.794 moles.
While we convert it into liters it will be
0.794 × 22.414 = 17.80L
The answer is 17.80 liters of water vapour which will be produced.
What is the name of the bone that makes up the backbone in humans
Vertebrae hope that helps :)
The elements beryllium, calcium, and strontium are all in group 2. What is the correct relationship of these elements regarding their ionization energy?
A.
Ca < Be < Sr
B.
Sr < Be < Ca
C.
Be < Ca < Sr
D.
Sr < Ca < Be
E.
Ca < Sr < Be
Answer:- choice d is correct. Sr<Ca<Be .
Explanations:- Br, Ca, and Sr are all elements of same group as they all have 2 valence electrons. As we move down in a group, a new shell is being added that increases the size of the atom. As the size of an atom increases, it is easy to remove the electron from it's outer most shell in it's gaseous state. Since, Be is above Ca and Ca is above Sr. The size increases in the order, Be < Ca < Sr. It means Be is the smallest one of them and so it's hard to remove from it's outer most shell and hence it's ionization energy is higher.
Sr is largest one in these three elements and so it's easy to remove outer most electron from it that means the ionization energy is least. Ca is between Be and Sr.
So, an increasing order of ionization energy is Sr<Ca<Be . Choice D is correct.
Answer:
D.
Sr < Ca < Be
Explanation:
PLATO
PLEASE HELP 10 POINTS!!!!
What is the molarity of HCl found in a titration where 50 ml of HCl is titrated with 50 ml of .1 M NaOH?
Answer is: the molarity of HCl found in a titration is 0.1 M.
Balanced chemical reaction between hydrochloric acid and sodium hydroxide:
HCl(aq) + NaOH(aq) → NaCl(aq) + H₂O(l).
From balanced chemical reaction: n(HCl) : n(NaOH) = 1 : 1.
n(HCl) = n(NaOH).
c(HCl) · V(HCl) = c(NaOH) · V(NaOH).
c(HCl) = c(NaOH) · V(NaOH) ÷ V(HCl).
c(HCl) = 0.1 M · 50 ml ÷ 50 ml.
c(HCl) = 0.1 M; molarity of hydrochloric acid.
PH of 0,035M HCl? How to count if your calculator hasn't got -lg?
Given information:
Concentration of HCl = 0.035 M
To determine:
pH of the solution
Explanation:
Hydrochloric acid, HCl is a strong acid. It will completely dissociate to give H+ and Cl- ions
HCl → H+ + Cl-
Hence the concentration of H+ = Cl- = 0.035M
Now, pH measures the strength of H+ ions in a given solution. It is expressed as:
pH = -log[H+]
pH (HCl) = -log(0.035) = 1.46
Ans: pH of 0.035M HCl is 1.46
an electric iron is used to remove wrinkles from clothes the electric iron is made of metal which property of this substance is most useful for this application
boiling point
density
electrical conductivity
thermal conductivity
thermal conductivity
Answer:
Thermal conductivity
Explanation:
When substances change into new substances, the process must involve:
a physical change
a chemical change
heat being produced
heat being absorbed
Answer is a chemical change.
As a result of a chemical reaction, a substance is changed into new substances which involves a chemical change.
During a chemical reaction, atoms of a molecule within a substance are rearranged into different combinations by combining with the atoms of another substance to form new substances.
An example of a chemical change is the composition of sodium chloride (salt) where the atoms of sodium and chlorine combine and rearrange themselves to form salt.
If granite and marble were exposed in an area with a hot and humid climate, _____.
A.the marble would weather more rapidly
B.the rocks would weather at the same rate
C.the granite would weather more rapidly
granite is a harder n tougher rock than marble so
If granite and marble were exposed in an area with a hot and humid climate,
A.the marble would weather more rapidly.
Rock weathering by hot and humid climate is dependent on the rock's strength and hardness. Marble is weaker and softer than Granite. So A. the marble would weather more rapidly.
How does substituting a hydrogen atom with a halogen in a hydrocarbon affect the resulting compound?
A.
All the single bonds in the original molecule change to double bonds.
B.
The boiling point of the new compound increases.
C.
The bonds between the carbon atoms in the molecule become weaker.
D.
The resulting compound is called a saturated hydrocarbon.
E.
The substitution allows each carbon atom to accept more than four valence electrons.
The boiling point of the new compound increases while substituting a hydrogen atom with a halogen in a hydrocarbon ,therefore option (b) is correct .
What do you mean by the boiling point of the substance ?The temperature at which substance change from liquid to the gaseous state is known as the boiling point.
The boiling point of a substance is the temperature at which both its liquid and vapor or gas states exist in equilibrium. Boiling point only occurs when heat is applied to the liquid substance.
It is also defined as the temperature at which liquid boils. The boiling point of water at sea level is 100∘C . It is equal to 373.15 on the Kelvin .
The boiling point of the new compound increases while substituting a hydrogen atom with a halogen in a hydrocarbon ,hence option (b) is correct .
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Answer:
B.
The boiling point of the new compound increases.
Explanation:
The correct electron configuration for Mn is
Question 4 options:
1s22s22p63s63d2
1s22s22p63s23p64s24p5
1s22s22p62d103s23p3
1s22s22p63s23p64s23d5
The correct electron configuration for Mn is 1s²2s²2p63s²3p64s²3d⁵.
Explanation:The correct electron configuration for Mn is 1s²2s²2p63s²3p64s²3d⁵. This means that manganese has a total of 25 electrons. The electron configuration represents the distribution of these electrons into different energy levels and orbitals. In the case of Mn, the 3d sublevel is partially filled with 5 electrons.
Which sample of matter is a single substance?
(1) air (3) hydrochloric acid
(2) ammonia gas (4) salt water
Any substance that is made up of only one type of atom or molecule is said to be a pure single substance whereas substance that is made up two or more different elements or molecule is said to be a mixture.
Air: Different types of gases are present in air that is nitrogen, water vapors, oxygen etc. So, air is a mixture.
Ammonia gas: It consists of only one molecule namely ammonia throughout the substance so it is a pure single substance.
Hydrochloric acid: It is made up by dissolving hydrochloric gas in water so it is a mixture.
Salt water: It is mixture as water and salt are being mixed which are two different substances.
Hence, ammonia gas is a single substance.
The formula of ammonia gas is NH₃. Ammonia gas is a single substances of matter. It is a pure kind of substance which consist of single phase of matter.
What is only one kind of matter is ?A substance is pure if it contains only one type of constituent material. A pure substance is stuff with consistent properties across its entire surface. Atoms are incredibly microscopic particles that make up all stuff.
All that is in the air is a concoction of different gases. Nitrogen, oxygen, which is necessary for both human and animal life, carbon dioxide, water vapor, and trace amounts of other elements make up the atmosphere (argon, neon, etc.)
Salt water contain salt and water in it so, it is a mixture of two molecules. Air is the mixture of many gases. Hydrochloric acid is formed by the reaction of hydrogen and chlorine. so they are not on kind of matter.
Thus, the ammonia gas is a sample of matter which is present in single substance. option 2 is correct.
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a) 3 and 4
b) 2 and 3
c) 1 and 2
d) 1 and 4
d) 1 and 4
Explanation:Elements are made up of particles known as atoms. Atoms of the same element have the same properties as the element.The atoms of an element may differ in terms of the number of neutrons and have a different mass number, such atoms are known as isotopes.However, the isotopes have an equal number of protons or atomic number.In this case, atom 1 has a mass number of 20 and an atomic number of 10 while atom 4 has a mass number of 21 and an atomic number of 21.Therefore, atom 1 and 4 are isotopes of element E.WHO IS GOOOD IN CHEMISTRY
HELP
ITS HARD
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HOMIE JUST TRY DONT HAVE TO ANSWER
Sorry for the delay, here's the Lewis Dot Structure of Chloramine
The Lewis structure for chloramine (NH2CI) is complete with all atoms having full octets and a total of 26 valence electrons used.
To complete the Lewis structure for chloramine (NH2CI), follow these steps:
Step 1: Determine the total number of valence electrons in the molecule.
Nitrogen (N) has 5 valence electrons.
Hydrogen (H) has 1 valence electron, but there are 2 hydrogen atoms, so we have 2 valence electrons.
Chlorine (Cl) has 7 valence electrons.
Total valence electrons = 5 (N) + 2 (H) + 7 (Cl) = 14 valence electrons.
Step 2: Connect the atoms with single bonds.
Place the nitrogen (N) in the center, and the hydrogen (H) and chlorine (Cl) atoms around it. Connect each atom to the nitrogen atom with a single bond.
H
N -- C -- Cl
/
H
Step 3: Distribute the remaining valence electrons to complete the octet of each atom.
Start by placing the remaining electrons around the hydrogen and chlorine atoms since they only need 2 electrons to complete their outer shells (duet rule).
H H
\ /
N -- C -- Cl
/
H
Step 4: Distribute the remaining valence electrons to complete the octet of the nitrogen atom.
Since nitrogen needs 8 electrons to complete its octet (octet rule), we place the remaining electrons around the nitrogen atom.
H H
| |
N - C - Cl
|| |
H H
Step 5: Check the total number of valence electrons used.
Count the number of valence electrons used in the Lewis structure.
2 (H) + 8 (N) + 8 (C) + 8 (Cl) = 26 valence electrons used.
Step 6: If there are extra valence electrons remaining, try forming double or triple bonds to complete octets.
In this case, all atoms have complete octets, and there are no extra valence electrons remaining.
The Lewis structure for chloramine (NH2CI) is complete with all atoms having full octets and a total of 26 valence electrons used.
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Which of the following is the correct skeleton equation for the reaction that takes place when solid phosphorus combines with oxygen gas to form diphosphorus pentoxide?
A. P(s) + O2(g) --> P2O5(s)
B. P2O5(s) --> P2(s) + O2(g)
C. P(s) + O(g) --> P5O2(g)
D. P(s) + O2(g) --> PO2(g)
Answer: Option (A) is correct.
Explanation:
In diphosphorus pentoxide there will be two phosphorous atoms and 5 oxygen atoms according to its name.
Therefore, the formula for diphosphorus pentoxide will be [tex]P_{2}O_{5}[/tex] and it is a solid.
Thus, the correct skeleton equation for the reaction that takes place when solid phosphorus combines with oxygen gas to form diphosphorus pentoxide will be as follows.
[tex]P(s)+ O_{2}(g) \rightarrow P_{2}O_{5}(s)[/tex]
The correct skeleton equation for the reaction that takes place when solid phosphorus combines with oxygen gas to form diphosphorus pentoxide is:
A. P(s) + O₂(g) ⇒ P₂O₅(s)
Let's consider which of the following is the correct skeleton equation for the reaction that takes place when solid phosphorus combines with oxygen gas to form diphosphorus pentoxide.
A. P(s) + O₂(g) ⇒ P₂O₅(s)Yes, this is the correct combination equation.
B. P₂O₅(s) ⇒ P₂(s) + O₂(g)
No, this is a decomposition equation. Also, elemental phosphorus is not diatomic.
C. P(s) + O(g) ⇒ P₅O₂(g)
No, since P₅O₂ is not diphosphorus pentoxide and elemental oxygen is diatomic.
D. P(s) + O₂(g) ⇒ PO₂(g)
No, since PO₂ is not diphosphorus pentoxide.
The correct skeleton equation for the reaction that takes place when solid phosphorus combines with oxygen gas to form diphosphorus pentoxide is:
A. P(s) + O₂(g) ⇒ P₂O₅(s)
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In 1980,the US produced 18.4 billion(10to the power of 9)pounds of phosphoric acid to be used in the manufacture of fertilizer.the average cost of the acid is 318$/ton.(1 Ton =2000 lb)what was the total value of the phosphoric acid produced?
18.4 * 10^9 lbs = (18.4 * 10^9)/2000 tons
Cost = ((18.4 * 10^9)/2000 ) * 318
Cost = $ 2925600000
Answer:
2'925.600'000.000 $ approximately 2,93 billion $
Explanation:
In order to get the total cost of the Phosphoric Acid produced, it's necessary to convert the Phosphoric Acid pounds into Tons using the given conversion and knowing that [tex]1 billion = 1'000.000'000.000[/tex] :
[tex]18.4 billon(lb) * \frac{1'000.000'000.000(lb)}{1 billon(lb)} *\frac{1(Ton)}{2000(lb)} =9.200'000.000(Ton)[/tex]
and knowing a Ton cost 318$ we can multiply by 318$ and get the result:
[tex]9.200'000.000(Ton) * \frac{318\$ }{1(Ton)} =2'925.600'000.000\$[/tex]
This is approximately 2,93 billion $.
Which of the following represents the number of grams of a solute in 100 grams of a solution?
Density
Molarity
Percent by mass
Volume
Answer:
Percent by mass
Explanation: I think
Percent by mass represents the number of grams of a solute in 100 grams of a solution. This is because it is the mass of the solute divided by the total mass of the solution, multiplied by 100.
Explanation:The option that represents the number of grams of a solute in 100 grams of a solution is Percent by mass. The definition of percent by mass in a solution, also known as mass percent, is the mass of the solute divided by the total mass of the solution, all multiplied by 100. Therefore, if you have a solution of 100 grams total, and you want to find out how many grams of solute you have in this solution, you would use percent by mass to calculate this.
Density, molarity, and volume have different uses and definitions in chemistry. Density is mass per unit volume, molarity is a measure of the concentration of a solute in a solution, and volume refers to the amount of space that matter occupies.
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An object will float when:
A. buoyant force is equal to the weight of the object
B. buoyant force is less than the weight of the object
C. density is equal to the weight of the object
D. density is greater than the weight of the object
Answer:
A. buoyant force is equal to the weight of the object
Explanation:
An object floats when the buoyancy is equal to the weight of the object. According to Archimedes Principle for flotation, the weight of the object should be equal to the weight of the water displaced by the submerged part of the object. If the weight of the object is greater than the weight of the water displaced by the submerged part of the object, it will sink.