You have 2000 g of radioactive substance with a half-life of 100 years four half-lives go by how many grams do you have the radioactive substance do you have left

after 4 half-lives, 125g is left

Explanation:

The half-life of a radioactive substance is the time it takes for the substance to decay by half its original mass.

In this example, we are asked to find the remaining mass after four half-lives.

What we will simply do is to reduce the starting mass by half, after each half-life decay. this is done as follows:

1st half-life decay: starting mass 2000g

final mass = 2000g ÷ 2 = 1000g

2nd half-life decay: starting mass = 1000g

final mass = 1000 ÷ 2 = 500

3rd half-life decay: starting mass = 500

final mass = 500 ÷ 2 = 250g

4th half-life decay: starting mass = 250g

final mass = 250 ÷ 2 = 125g

∴ after 4 half lives, 125g is left

because of all the things that happen around the us, many people get into arguments which sadly could get physical, but we should actually make a change for that.

a. the law of proportion states the combination of 2 atoms in a specific ratio to produce multiple compounds such as the given statement of question ‘1st compound contains 88.8 % cu ’ indicates 88.8 g of cu is present along with 11.2 g oxygen in 100 g of compound whereas the statement ‘2st compound contains 79.9 % cu ’ indicates 79.9 g of cu is present along with 20.1 g oxygen in 100 g of compound

1st compound contains 88.8 g cu

for cu

m = 63 g /mol

atomic % = 88.8 /63 = 1.42

for o

m = 16 g /mol

atomic % = 11.2 /16 = 0.7

b. the emperical formula of 1st compound is

cu1.4o0.7

cu2o