All categories

3 years ago

After 184.5 years, onky 0.625 grams of an original 20 gram sample of a radioactive isotope is left. Find the half life

Chemistry

1 answer:

kakasveta [241]3 years ago

8 0

Answer:

half-life=T= 36.9 years

Explanation:

As we know that

N ( t ) = N ( 0 ) ⋅ 0.5 ^(t/ T )

N ( 0 ) =the number of atoms you start with=20 gram

and N ( t )= the number of atoms left=0.625 grams

after a certain time=t=184.5 years

T=half life of a nuclide=?

Putting value in above equation we get

half-life=T= 36.9 years

You might be interested in

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

The Nutrition Facts label for crackers states that one serving contains 19 g of carbohydrate, 4 g of fat, and 2 g of protein. Wh

sp2606 [1]

Answer: The amount of kilocalories contained in the given serving of crackes is 0.120 kCal

Explanation:

As per the USDA:

Carbohydrates provide 4 calories per gram, protein provides 4 calories per gram, and fat provides 9 calories per gram

We are given:

Mass of fat in the crackers = 4 g

Mass of carbohydrates in the crackers = 19 g

Mass of protein in the crackers = 2 g

Conversion factor used: 1 kCal = 1000 Cal

Applying unitary method:

For Fat:

1 gram of fat provides 9 calories

So, 4 gram of fat will provide = $\frac{9}{1}\times 4=36Cal=0.036kCal$

For Carbohydrates:

1 gram of carbohydrates provides 4 calories

So, 19 gram of carbohydrates will provide = $\frac{4}{1}\times 19=76Cal=0.076kCal$

For Proteins:

1 gram of proteins provides 4 calories

So, 2 gram of fat will provide = $\frac{4}{1}\times 2=8Cal=0.008kCal$

Total kilocalories per serving = [0.036 + 0.076 + 0.008] kCal = 0.120 kCal

Hence, the amount of kilocalories contained in the given serving of crackes is 0.120 kCal

8 0

3 years ago

What else is produced during the combustion of butane, C4H10?

denpristay [2]

Another product: CO₂

<h3>Further explanation</h3>

Given

Reaction

2C₄H₁₀ + 13O₂⇒ 8__+ 10H₂O

Required

product compound

Solution

In the combustion of hydrocarbons there can be 2 kinds of products

If there is excess Oxygen, you will get Carbon dioxide(CO₂) and water in the product

If Oxygen is low, you'll get Carbon monoxide(CO) and water

Or in other ways, we can use the principle of the law of conservation of mass which is also related to the number of atoms in the reactants and in the products

if we look at the reaction above, there are C atoms on the left (reactants), so that in the product there will also be C atoms with the same number of C atoms on the left

2C₄H₁₀ + 13O₂⇒ 8CO₂+ 10H₂O

5 0

3 years ago

Read 2 more answers

Can anyone help with 5 through 8? Please :(

Aleksandr [31]

Answer:

The answer to your question is below

Explanation:

5) Fe₂O₃(s) + 3H₂O ⇒ 2Fe(OH)₃ (ac) Synthesis reaction

6) 2C₄H₁₀(g) + 13O₂(g) ⇒ 8CO₂ (g) + 10H₂O Combustion reaction

7) 2NO₂ (g) ⇒ 2O₂ (g) + N₂ (g) Decomposition reaction

8) H₃P (g) + 2O₂ (g) ⇒ PO (g) + 3H₂O Single replacement reaction

4 0

3 years ago

Which of the following is NOT a property of an acid

ipn [44]

The answer is B. Acid turns blue litmus paper to red

4 0

3 years ago

After 184.5 years, onky 0.625 grams of an original 20 gram sample of a radioactive isotope is left. Find the half life​

After 184.5 years, onky 0.625 grams of an original 20 gram sample of a radioactive isotope is left. Find the half life