If you have 100 g of radioactive isotope with a half-life of 10 years:
How much of the isotope will you have left after 10 years?
How much of the isotope will you have left after 20 years?
How many Half lives Will occur in 40 years?

Answer: 0.088 moles

Explanation:

Parameters given:

Mass of AgNO3 = 15.0g

To know the number of moles, given such parameter, we need to find and use the molecuar weight formular. The molecuar weight is mass per mole

Molecular weight = mass / mole

Molecular weight of AgNO3

Ag + N + 03

107.8682 + 14.0067 + 15.9994(3)

(Note, that the weight of each compounds are standards)

= 169.8731g/mole

Using our molecular weight formular

Moles of AgNO3 in 15.0g

Let Number of Moles be represented as Y

169.8731g/mole = 15.0g / Y

Therefore,

Y = 169.8731 / 15.0g

Y = 0.088 moles

No of Moles of AgNo3 in 15.0g = 0.088moles

The most efficient method would be to passing a magnet through the mixture.

Explanation:

a) passing a magnet through the mixture

It is the most efficient method to separate the iron fillings and the salt. The iron will be attracted by the magnet, because the presence of the unpaired electrons in the iron which induces paramagnetic properties and it will be attracted by the magnet, while the salt, which most probably sodium chloride which does not have unpaired electrons so it will be a diamagnetic compound that is not be attracted by a magnet.

b) sorting the mixture by hand

It is a ineficient way to separate the iron from the salt because it will require a lot of energy and time.

c) distilling the mixture

It is extremely hard to do that because iron and salt have very high boiling points.

Learn more about:

separating mixtures

https://brainly.com/question/64216

https://brainly.com/question/13360045

#learnwithBrainly

The best way to separate a mixture of iron filings and salt is to use a magnet, which attracts the iron. The other methods (sorting by hand, distilling) are less efficient and not suitable for this mix.

The most efficient method to separate a mixture of iron filings and salt is to pass a magnet through the mixture. This is because iron is magnetic, while salt is not. The magnet will attract the iron filings and leave the salt behind. Following this process, you could rinse or carefully brush the iron filings off the magnet. This is a simple process called magnetic separation.

Sorting the mixture by hand or distilling the mixture is not recommended. Manually sorting can be tedious and might not effectively separate all the iron filings while distilling is usually used to separate liquid mixtures, not solids like iron filings and salt.

https://brainly.com/question/34301663

#SPJ12

Answer:

[tex]\large \boxed{\text{0.30 g }}[/tex]

Explanation:

1. Calculate the moles of NaOH

[tex]\text{Moles of NaOH} = \text{0.050 L solution} \times \dfrac{\text{0.15 mol NaOH}}{\text{1 L solution}} = \text{0.0075 mol NaOH}[/tex]

2. Calculate the mass of NaOH

[tex]\text{Mass of NaOH } = \text{0.0075 mol NaOH } \times \dfrac{\text{40.00 g NaOH }}{\text{1 mol NaOH }} = \textbf{0.30 g NaOH}\\\\\text{You need $\large \boxed{\textbf{0.30 g of NaOH}}$ to prepare the solution}[/tex]

Two compounds can have same percentage composition but different molar mass, where the composition of each element contributed into the total mass can be same for two compounds irrespective of their molar mass.

Percentage composition of a compound is the mass by percent of its constituent elements of groups.  Molecular mass of a compound is the sum of the mass of its constituent elements.

Let AB₂ be a compound and the total molecular mass be X,the percentage of A be a% and that of b being b%, where b will be greater since there are 2 B groups.

There can be compounds with a % of A and b% of B but with different molar mass. Thus, there will be compounds which contains same mass percent of one elements.

To find more on percent composition, refer here:

https://brainly.com/question/17505281

#SPJ3

Final answer:

Two compounds can have the same percentage composition but different molecular masses because they can be structural isomers, which have the same number and types of atoms but arranged differently resulting in different properties and molar masses.

Explanation:

Compounds with Same Percentage Composition and Different Molecular Masses

Two compounds can have the same percentage composition but different molecular masses due to the phenomenon of isomerism. Isomers are molecules that have the same molecular formula, meaning the same number and types of atoms, but with the atoms arranged in a different manner. This results in different structures and potentially different physical properties, including molecular masses. The percentage composition only reflects what percent of the compound's total mass is made up by each type of atom, regardless of the compound's structure.

For instance, structural isomers have the same chemical composition but different arrangements of atoms and different chemical bonding, leading to different molar masses. To determine the percentage composition, one would divide the atomic mass of each element by the total molar mass of the molecule. However, this calculation doesn't account for the structural differences between isomers.

Examples of this include butane and isobutane, both of which have the molecular formula C4H10 but differ in structure and therefore in their molar mass. Such scenarios illustrate the importance of not only considering the percentage composition but also the molecular structure when identifying and comparing substances.

Answer:

Blue: 440 nm; 6.81 × 1014 Hz; 4.51 × 10−19 J.

Explanation:

I know

The frequency of blue light with a wavelength of 440nm is calculated using the speed of light and the wavelength, resulting in a frequency of approximately 6.818  imes 10¹⁴ Hz.

The frequency of blue light with a wavelength of 440nm can be calculated using the speed of light and the formula for frequency, which is frequency (f) = speed of light (c) / wavelength ( ambda). Given that the speed of light (c) is 3.00  imes 10^8 ms⁻¹, and the wavelength ( ambda) of blue light is 440nm (which is 440  imes 10⁻⁹m when converted to meters), we can calculate the frequency as follows:

f = c /  ambda

f = (3.00  imes 10^8 ms⁻¹,  / (440  imes 10⁻⁹ m)

After performing the calculation:

f  = 6.818  imes10¹⁴Hz

Therefore, the frequency of blue light with a wavelength of 440nm is approximately 6.818  imes 10¹⁴ Hz.

Answer:Brain

Explanation:

Answer:

It is the nerves :)

Explanation:

Answer:

The  volume (in ml) of a 3.57 M solution of [tex]ZnBr_2[/tex] that contains 0.884 moles of  [tex]ZnBr_2[/tex] is 247.61g mL

Explanation:

According to the definition of Molarity

which sates

"The amount of moles of a substance present in one litre of the solution is called as Molarity."

3.57M [tex]ZnBr_2[/tex] solution implies that 1000 mL of the solution conatins 3.57Moles of [tex]ZnBr_2[/tex]

Hence , 3.57 moles of [tex]ZnBr_2[/tex] is present in the 1000 ml of solution

Now,

In 1 mole of [tex]ZnBr_2[/tex] is  present in the =[tex]\frac{1000}{3.57}[/tex]ml of solution

Similarily ,

In 0.884  moles of[tex]ZnBr_2[/tex] is  present in the [tex]\frac{1000\times 0.884}{3.57}[/tex] of solution= 247.61g mL

Answer:

Explanation:

Chemical equation;

2C₁₀H₂₂ + 31O₂  → 20CO₂ + 22H₂O

a) how many moles of O₂ are needed to completely react with 1.0 mole of C₁₀H₂₂?

Given data:

Moles of C₁₀H₂₂ = 1.0 mol

Moles of O₂ needed = ?

Solution:

we will compare the moles of C₁₀H₂₂ with O₂.

                            C₁₀H₂₂          :            O₂

                                 2              :             31

                                 1.0            :            31/2×1.0 = 15.5 mol

So 15.5 moles of oxygen are needed to react with 1.0 moles of C₁₀H₂₂ .

B) if a car produces 44 g of CO₂, how many grams of C₁₀H₂₂ are used up in the reaction?

Given data:

Mass of CO₂ = 44 g

Mass of C₁₀H₂₂ = ?

Solution:

Number of moles of CO₂:

Number of moles = mass/ molar mass

Number of moles = 44 g/ 44 g/mol

Number of moles = 1 mol

Now we will compare the moles of CO₂ with C₁₀H₂₂.

                          CO₂       :          C₁₀H₂₂

                             20       :              2

                              1         :           2/20×1 = 0.1 mol

Mass of C₁₀H₂₂:

Mass = number of moles × molar mass

Mass = 0.1 mol  × 142.3 g/mol

Mass = 14.23 g

14.23 g of C₁₀H₂₂ are used up in this reaction.

c) if you add 28.8 g of C₁₀H₂₂ to your fuel, how many moles of O₂  are used up in the reaction?

Given data:

Mass of C₁₀H₂₂ = 28.8 g

Moles of oxygen used = ?

Solution:

Number of moles of C₁₀H₂₂ = mass/ molar mass

Number of moles of C₁₀H₂₂ = 28.8 g /142.3 g/mol

Number of moles of C₁₀H₂₂ = 0.20 mol

Now we will compare the moles of C₁₀H₂₂ with oxygen.

                      C₁₀H₂₂            :            O₂

                         2                  :             31

                       0.20               :             31/2×0.20 = 3.1 mol

By adding 28.8 g of C₁₀H₂₂ 3.1 moles of oxygen will used.

Answer:

Dunes are loose sand hills.

Loess is a compacted wind-blown formation of sediment.

Explanation:

Sand dunes are, as their name implies, made of sand which is itself made of tiny quartz pieces. Sand dunes are present where there is a ready source of broken down sandstone or other type of rock and wind to transport the sand. The dunes are mobile and loose and migrate over time.

Loess comes in vast formations and was created in a very different way. In the last ice age, winds from the north carried sediments loosened and ground by glaciers southwards. There, the sediments accumulated in large formations and became compacted over time.

An atom is smaller than an element since an element is composed of many atoms. Atoms make up the smallest unit of an element that maintains the element's properties. The size of atoms varies and can be compared using the periodic table, with atoms generally increasing in size down a group and decreasing across a period.

When comparing the size of an atom to that of an element, it is essential to understand that these terms describe different concepts in chemistry. An atom is the smallest unit of matter that retains the properties of an element, meaning it is a single particle. Conversely, an element is a pure substance made up of one type of atom. Therefore, while atoms are the tiny building blocks that make up elements, the term 'element' refers to the collective group of these atoms when considered as a whole. For example, a gold nugget is composed of multiple gold atoms but is still referred to as the element gold. Given this distinction, atoms are the smaller of the two when comparing size.

Size-wise, individual atoms can vary depending on the type of element. For instance, a helium atom is smaller than a lead atom. If we refer to the periodic table, we can compare the relative sizes of atoms based on their position. Typically, atoms increase in size as you move down a group (column) and decrease as you move across a period (row) from left to right. Hence, elements found further down and to the left of the periodic table generally have larger atoms than those towards the top right. However, it's often necessary to consider atomic radii and various other factors to make precise comparisons between atom sizes.

Answer: Brownian motion or pedesis is the random motion of particles suspended in a fluid resulting from their collision with the fast-moving molecules in the fluid. This pattern of motion typically alternates random fluctuations in a particle's position inside a fluid sub-domain with a relocation to another sub-domain.

Answer:

The correct answer is A balanced

Explanation:

Redox reaction belongs to specific type of chemical or biochemical reaction in which oxidation and reduction occurs simultaneously.

      For example

           6CO2+12H2O=C6H12O6+6O2+6H2O

The above reaction is a redox reaction because in this reaction CO2 is reduced to form glucose whereas H2O is being oxidized to form O2.

   Redox equations are balanced when the total increase in the oxidation number equals the total decrease in the oxidation number.

Answer:

A. balanced

Explanation:

Hello,

In this case, redox reactions undergo when one the elements at the reactants suffers an increase in its oxidation state and other elements suffers a decrease in its oxidation state. Thus, one could consider the following example:

[tex]H_2+I_2\rightarrow HI[/tex]

In that case, both hydrogen and iodine have zero as their oxidation states at the reactants whereas they go +1 and -1 respectively at the hydroiodic acid as shown below:

[tex]H_2^0+I_2^0\rightarrow H^+I^-[/tex]

In such a way, each hydrogen increases by 1 electron (two electrons in total as there two hydrogens) and iodine decreases by 1 electron (two electrons in total as there two iodines). Thus, the balance turns out:

[tex]H_2^0\rightarrow 2H^++2e^-\\I_2^0+2e^-\rightarrow 2I^-\\\\\\2H_2+2I_2\rightarrow 4HI\\\\H_2+I_2\rightarrow 2HI[/tex]

Therefore, redox equations are A. balanced when the total increase in oxidation numbers equals the total decrease in oxidation.

Best regards.

Answer: 13 proton, 10 electron and 14 neutron.

Explanation: electron are 10 because 3 electrons are transfer to other atom.

Answer:

Proton = 13

Electron = 10

Neutron = 14

Explanation:

Al3+ means Al that  has lost 3 electrons. Al has 13 protrons and 13 electrons. Having lost 3 electrons, Al3+ is left with 10 electrons.

Neutron + protron = relative atomic number

n + 13 = 27

n = 27 - 13 = 14

Answer:

The correct answer is c they are specialized.

Explanation:

Human body contain various types of cells and each specific type of cell performs specific functions.

  For example nerve cells help in propagation of action potential from one neuron to the next.

    Heart cells of our body act as a pump.Basically heart cells pump blood.

    Blood cells helps in transport of various biomolecules and fight against invaded pathogens.

  Lung cells helps in the exchange of oxygen and carbon dioxide gas to and from our body.

  kidney cells helps in the filtration of blood and formation of urine

Answer:                 (C They are specialized

Explanation:

Answer:

N₂ + 3H₂  → 2NH₃

Explanation:

Nitrogen react with hydrogen and form ammonia. The one mole of nitrogen gas react with two moles of hydrogen and form two moles of ammonia.

The oxidation state of nitrogen is -3 while that of hydrogen is +1. That's why two balance the charge one with one nitrogen atom three hydrogen atom react and with two nitrogen atom with a charge of -6 six hydrogen atoms are attached (+6).

Chemical equation:

N₂ + H₂  → 2NH₃

Balanced chemical equation;

N₂ + 3H₂  → 2NH₃

The balanced equation for the synthesis reaction between nitrogen and hydrogen to produce ammonia is N2 + 3H2 → 2NH3.

The balanced equation that shows the product formed when nitrogen with an oxidation state of -3 undergoes a synthesis reaction with H2, which has an oxidation state of +1, is:

N2 + 3H2 → 2NH3

In this reaction, one molecule of N2 reacts with three molecules of H2 to produce two molecules of NH3. The coefficients in the balanced equation represent the mole ratio required for the reaction to occur.

Ni (s) + 2 HNO₃ (aq) → Ni(NO₃)₂ (aq) + H₂ (g)

Explanation:

We have the following balanced chemical equation:

Ni (s) + 2 HNO₃ (aq) → Ni(NO₃)₂ (aq) + H₂ (g)

where:

(aq) - aqueous  (dissolved in water)

(g) - gaseous

To balance the chemical equation the number of atoms of each element entering the reaction have to be equal to the number of atoms of each element leaving the reaction, in order to conserve the mass.

Learn more about:

balancing chemical equations

https://brainly.com/question/13915102

#learnwithBrainly

Answer:

A

Explanation:

Earthquakes are said to occur at faults where tectonic plates run into each other because they have been observed to occur at those tectonic plate boundaries.

Part of the evidence for the theory of plate tectonics is the predictable occurrence of earthquakes and volcanoes along plate boundaries. The Pacific Ring of Fire is an example of a seismically active zone that has been observed and labelled based on the noted activity.

Iodine-131 has a shorter half-life than cobalt-60.

We are given;

We are supposed to explain the difference between the two instances;

We need to define half life;

Answer:

hydrogen ions

Explanation:

because acid is the specie that have ability to donate proton or forming bond with electron pair

Acidic solutions have high concentrations of hydrogen ions.

When an acid dissociates in aqueous solution, it releases hydrogen ions, leading to increased H+ concentration and making the solution acidic. This is due to the higher proportion of H+ ions compared to hydroxide ions in acidic solutions.

Answer:

Elements :)

Explanation:

Neon (Ne), being an element, is the substance that cannot be decomposed by chemical means from the given list. All other options are chemical compounds that can be decomposed into elements.

The question is about identifying a substance that cannot be decomposed by chemical means from a given list. Substances that cannot be chemically decomposed are known as elements, which are the most basic form of matter that cannot be broken down into simpler substances. Based on the options provided (Ne, N₂O, HF, H₂O), Neon (Ne) is an element and thus cannot be decomposed chemically into simpler substances.

The rest of the substances are chemical compounds: N₂O (nitrous oxide), HF (hydrogen fluoride), and H2O (water). These compounds can be decomposed into their elements by chemical reactions, such as hydrolysis or electrolysis for water. Therefore, the correct answer is Ne, which is an inert noble gas and an element that cannot be decomposed by chemical means. Option A

Taxonomy is the procedure for ranking plants.

Explanation:

The plants are ranked depending upon the resemblances and differences it has from another kind of plants. They can be ranked depending upon their leaves, roots, stems and other structures. They are defined into more general categories depending on the similar traits in the same group.

The plants are broadly classified into vascular and non vascular .Example, a flowering plant is a higher green plant and based on its gross structure does lie in the kingdom of Plantae, not in fungus or bacteria.

Answer:

percentage yield = 88.25%

Explanation:

Firstly, write the chemical reaction and balance the equation.

Potassium react with oxygen to produce potassium oxide.

K + 02 → K2O

Balance the equation

4K + 02 → 2K2O

The limiting reactant is K so the yield of potassium oxide can be calculated using grams for potassium.

atomic mass of K = 39.1g/mol

grams for 4 mole of potassium =  4(39.1) = 156.4 g

grams for 2 moles of K2O = 2( 39.1 × 2 + 16) = 188.4 g

If 156.4 g of K produces 188.4 g of K2O

6.92 g of K will produce ? gram of K2O

cross multiply

grams of K2O = 6.92 × 188.4/156.4

grams of K2O = 1303.72/156.4

grams of K2O = 8.33585677749

grams of K2O = 8.34 g

percentage yield = actual yield/theoretical yield × 100

actual yield = 7.36 g

theoretical yield = 8.34 g

percentage yield = 7.36/8.34 × 100

percentage yield =         736/8.34

percentage yield = 88.2494004796%

percentage yield = 88.25%

Taking into account definition of percent yield, the percent yield for the reaction is 88.25%.

In first place, the balanced reaction is:

4 K + O₂ →2 K₂O

By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:

The molar mass of the compounds is:

Then, by reaction stoichiometry, the following mass quantities of each compound participate in the reaction:

The limiting reagent is one that is consumed first in its entirety, determining the amount of product in the reaction. When the limiting reagent is finished, the chemical reaction will stop.

To determine the limiting reagent, it is possible to use a simple rule of three as follows: if by stoichiometry 32 grams of O₂ reacts with 156 grams of K, 4.28 grams of O₂ reacts with how much mass of K?

[tex]mass of K=\frac{4.28 grams of O_{2} x 156 grams of K}{32grams of O_{2}}[/tex]

mass of K= 20.865 grams

But 20.865 grams of K are not available, 6.92 grams are available. Since you have less mass than you need to react with 4.28 grams of O₂, K will be the limiting reagent.

Considering the limiting reagent, the following rule of three can be applied: if by reaction stoichiometry 156 grams of K form 188 grams of K₂O, 6.92 grams of K form how much mass of K₂O?

[tex]mass of K_{2} O=\frac{6.92 grams of Kx188 grams of K_{2} O}{156 grams of K}[/tex]

mass of K₂O= 8.34 grams

Then, 8.34 grams of K₂O can be produced from 6.92 grams of K and 4.28 grams of O₂.

The percent yield is the ratio of the actual return to the theoretical return expressed as a percentage.

The percent yield is calculated as the experimental yield divided by the theoretical yield multiplied by 100%:

[tex]percent yield=\frac{actual yield}{theoretical yield}x100[/tex]

where the theoretical yield is the amount of product acquired through the complete conversion of all reagents in the final product, that is, it is the maximum amount of product that could be formed from the given amounts of reagents.

In this case, you know:

Replacing in the definition of percent yields:

[tex]percent yield=\frac{7.36 grams}{8.34 grams}x100[/tex]

Solving:

percent yield= 88.25%

Finally, the percent yield for the reaction is 88.25%.

Learn more about

the reaction stoichiometry:

brainly.com/question/24741074

brainly.com/question/24653699

percent yield:

brainly.com/question/14408642?referrer=searchResults

Answer:

The soil is more developed and more fertile.

Explanation:

The lack of immediate decomposers in temperate forests allows the vertical profile of the soil to develop more thanks to the accumulation of plant matter. As a result, the soils of temperate forests are eroded less easily by the element and they also tend to be more fertile than rain forest soils due to the slow decomposition of organic matter.

Here’s a hint for you…the Latin root for color is "chroma"

The Latin root for body is "soma"...

That should help you figure out the answer for yourself!

P.S. The answer is Chromosomes.

Hope this helps

energy of the wave is equal to 43.6 × 10⁻²¹ J

Explanation:

The energy of a wave knowing the frequency is calculated using the following formula:

energy = plank constant × frequency

energy = 6.63 x 10⁻³⁴ J·s × 6.58 × 10¹³ s⁻¹ (Hz)

energy = 43.6 × 10⁻²¹ J

Learn more about:

energy of a electromagnetic wave

https://brainly.com/question/518150

https://brainly.com/question/1441437

#learnwithBrainly

Answer:

Mass = 547.2 g

Explanation:

Given data;

Mass of F₂ = ?

Moles of F₂ = 14.4 mol

Solution:

Formula

Number of moles = mass/ molar mass

Mass = number of moles × molar mass

Molar mass of F₂ =  38 g/mol

Mass = 14.4 mol × 38 g/mol

Mass = 547.2 g

The mass of 14.4 moles of F₂ is 547.2 grams.

To solve this, we need to know the molar mass of fluorine gas (F₂). Each fluorine atom has an atomic mass of approximately 19.0 g/mol. Since F₂ is a diatomic molecule, its molar mass is:

19.0 g/mol × 2 = 38.0 g/mol

Now, we multiply the molar mass by the number of moles given:

14.4 mol × 38.0 g/mol = 547.2 g

Thus, the mass of 14.4 moles of F₂ is 547.2 grams.

TRUE

Explanation:

Covalent bonding occurs when pairs of electrons are shared by atoms. Atoms will covalently bond with other atoms in order to gain more stability. By sharing their outer most electrons, atoms can fill up their outer electron shell and gain stability. So, it is true.

To react completely with 3.70g of dry slaked lime, 1.12 liters of chlorine gas would be required at STP, based on mole calculations and the ideal gas law.

To calculate the volume of chlorine gas that would react completely with 3.70g of dry slaked lime (Ca(OH)₂), we need to follow a series of steps:

First, we calculate the moles of Ca(OH)₂ using its molar mass (Ca = 40, O = 16, H = 1). The molar mass of Ca(OH)₂ is: (40) + (2 x 16) + (2 x 1) = 74 g/mol.

Next, we find the moles of Ca(OH)₂ in 3.70g by dividing the mass by the molar mass: moles of Ca(OH)₂ = 3.70 g / 74 g/mol = 0.05 moles.

According to the equation, 1 mole of Ca(OH)₂ reacts with 1 mole of Cl₂. Therefore, we need 0.05 moles of Cl₂.

We use the ideal gas law at standard temperature and pressure, where 1 mole of a gas occupies 22.4dm³. The volume of Cl₂ needed is 0.05 moles x 22.4 dm³/mole = 1.12 dm³, or 1.12 liters.

Therefore, 1.12 liters of chlorine gas would be required to react completely with 3.70g of dry slaked lime at standard temperature and pressure (STP).

Answer:

soil A mixture of weathered rock and decayed plants and animals. Plants need soil to grow. Soil is the top layer of Earth's land surface, in many places.

Explanation:

Soil is the mixture composed of eroded rocks, organic matter from decayed plants and animals, minerals, and other materials vital for plant growth and ecological foundations.

The material you're asking about, which is a mixture of small pieces of rock with decayed plants and animals, is known as soil. Soil is a blend of various components, including eroded rock, minerals, organic matter, and other materials. These ingredients are critical for supporting plant life and form the fundamental layers of terrestrial ecosystems.

The organic matter in soil typically comes from decaying plant and animal matter, which can vary from freshly fallen leaves to more fully decomposed materials, known as detritus. Additionally, soil may include biologic precipitates, fragments of rocks such as sand, silt, or clay, and in some cases, paths created by earthworms and burrows from moles.

Answer:

1st you read the column that has the subject then the tally column last you determine/read the frequency column

Explanation: