I don't understand what the answer choices mean

You would know you were in the troposphere If?

lora16 [44]

It were raining on you

7 0

3 years ago

Which nitrogenous base is NOT found in DNA? *

scoundrel [369]

Answer:

c. uracil

Explanation:

uracil is not found in DNA. the missing base would be thymine

5 0

3 years ago

Strontium-90 is a radioisotope that will decrease in mass by one-half every 29 years. How many years will it take for a 10.0-gra

Lelechka [254]

Answer: It will take 29 years for a 10.0-gram sample of strontium-90 to decay to 5.00 grams

Explanation:

Radioactive decay process is a type of process in which a less stable nuclei decomposes to a stable nuclei by releasing some radiations or particles like alpha, beta particles or gamma-radiations. The radioactive decay follows first order kinetics.

Half life is the amount of time taken by a radioactive material to decay to half of its original value.

Half life is represented by $t_{\frac{1}{2}$

$t_{\frac{1}{2}=\frac{0.693}{\lambda}$

$\lambda$ = rate constant

Given : Strontium-90 decreases in mass by one-half every 29 years , that is half life of Strontium-90 is 29 years.

As half life is independent of initial concentration, it will take 29 years for a 10.0-gram sample of strontium-90 to decay to 5.00 grams as the amount gets half.

7 0

3 years ago

Which statement describes a chemical property of sodium

Alenkasestr [34]

Answer:

Option b is show the chemical property of sodium....

4 0

3 years ago

A sample of gas contains 0.1700 mol of NH3(g) and 0.2125 mol of O2(g) and occupies a volume of 17.8 L. The following reaction ta

telo118 [61]

Answer:

The volume of the sample after the reaction takes place is 19.78 L.

Explanation:

The given variables are;

Number of moles of NH₃(g) = 0.1700 mol

Number of moles of O₂(g) = 0.2125 mol

Volume occupied by the mixture = 17.8 L

The reaction

4NH₃(g) + 5O₂(g) → 4NO(g) + 6H₂O(g)

Then takes place

That is 4 moles of NH₃(g) reacts with 5 moles of O₂(g) to produce 4 moles of NO(g) and 6 moles of H₂O(g).

Since there are less number of moles of NH₃(g) (= 0.1700 mol) in the mixture, we factor the above equation by the number of moles of NH₃(g) present.

That is,

1 moles of NH₃(g) reacts with 5/4 moles of O₂(g) to produce 1 moles of NO(g) and 3/2 moles of H₂O(g).

Therefore,

0.1700 mol of NH₃(g) reacts with 5/4×0.1700 moles of O₂(g) to produce 0.1700 moles of NO(g) and 3/2×0.1700 moles of H₂O(g).

Which gives

0.1700 mol of NH₃(g) reacts with 0.2125 moles of O₂(g) to produce 0.1700 moles of NO(g) and 0.255 moles of H₂O(g).

Therefore, all of the NH₃(g) and O₂(g) are consumed in the reaction and the present gases in sample then becomes

0.1700 moles of NO(g) and 0.255 moles of H₂O(g).

Total number of moles of reactant = 0.17 + 0.2125 = 0.3825

Total number of moles of product formed = 0.17 + 0.255 = 0.425

However, Avogadro's law states that equal volume of all gases at the same temperature and pressure contains equal number of molecules.

That is volume occupied by 0.3825 moles of gas = 17.8 L

Therefore the volume occupied by 0.425 moles of gas = 17.8×0.425/0.3825 L = 19.78 L

3 0

3 years ago