All categories

4 years ago

The half-life of Radium-226 is 1590 years. If a sample contains 100 mg, how many mg will remain after 4000 years?

1 answer:

4 0

We can calculate the amount left after 4000 years by using the half-life equation. It is expressed as:

A = Ao e^-kt

where A is the amount left at t years, Ao is the initial concentration, and k is a constant.

From the half-life data, we can calculate for k.

1/2(Ao) = Ao e^-k(1590)
k = 4.36 x 10^-4

A = 100 e^-<span> 4.36 x 10^-4(4000)
</span>A = 17.48 mg

You might be interested in

How are oxides of nitrogen formed?

mariarad [96]

By heat getting on it and the heat spreads gas witch makes nitrogen

7 0

3 years ago

Why is the solubility of khp in water greater than many fatty acids with six or more carbons?

Georgia [21]

Solubility of khp in water is greater than many fatty acids because khp is a polar substance while fatty acids are non-polar. Khp has positive and negative charges which help it to dissociate into ions when it dissolves in water. Fatty acids on the other hand contain long unbranched hydrocarbons with one end having a carboxylic acid group. This make water molecules to repel from them because no part of the fatty acid molecules have any charge.

3 0

4 years ago

The equilibrium constant for the formation of ammonia from nitrogen and hydrogen is 1.6 × 102. what is the form of the equilibri

Nimfa-mama [501]

Answer: The expression for equilibrium constant is $\frac{[NH_3]^2}{[H_2]^3[N_2]}$

Explanation: Equilibrium constant is the expression which relates the concentration of products and reactants preset at equilibrium at constant temperature. It is represented as $k_c$

For a general reaction:

$aA+bB\rightleftharpoons cC+dD$

The equilibrium constant is written as:

$k_c=\frac{[C]^c[D]^d}{[A]^a[B]^b}$

Chemical reaction for the formation of ammonia is:

$N_2+3H_3\rightleftharpoons 2NH_3$

$k_c=1.6\times 10^2$

Expression for $k_c$ is:

$k_c=\frac{[NH_3]^2}{[H_2]^3[N_2]}$

$1.6\times 10^2=\frac{[NH_3]^2}{[H_2]^3[N_2]}$

8 0

3 years ago

HELP ASAP!! DON'T COPY FROM G00GLE

allsm [11]

Parts of respiratory system:

Nose and Nasal Cavity, mouth, Pharynx, Larynx, Trachea, Bronchi and Bronchioles, Lungs and Muscles of Respiration.

Respiratory system function:

Your respiratory system is the network of organs and tissues that help you breathe. This system helps your body absorb oxygen from the air so your organs can work. It also cleans waste gases, such as carbon dioxide, from your blood.

Alveoli:

Alveoli are tiny sacs of air in your lungs that take up the oxygen you breathe and keep it going. The alveoli ventilate, diffuse and peruse in your lungs.

3 0

3 years ago

PLEASE HELP WILL MARK YOU AS BRAINLEST

kozerog [31]

It is a very large seamount and island created by hot-spot volcanism

7 0

3 years ago