What percentage of a radioactive substance remains after 7.00 half-lives have elapsed?

Explanation:

We want to know the percentage of the radio active element after 7half life

Let assume the original mass or quantity of the radioactive element is No

After first half life it remains No/2

Second half life No/4

Third half life No/8

Fourth half life No/16

Fifth half life No/32

Sixth half life No/64

Seventh half life No/128

So after the seventh half life the radioactive element has decay to No/128

Then, the that remain is

The remaining amount / Original amount × 100

%remain = (No/128 / No) × 100

No cancel No

%remain = 100/128

%remain = 0.78%

the following is queen elizabeth’s purposes:

- to encourage the parliament that the technique of picking successors to the seat based merely on birthright needs to be reviewed.

- (not) to convince the parliament that her kid should not be measured as a likely choice for heir to the english power.

- to persuade the parliament that merely since she has a child does not assure that the kid will be a capable leader.

- to sway the parliament how shattering it could be if they proceeded discourteously concerning her or her child.

find the surface area of the sphere to the nearest square unit. use a calculator.

a. 254 in.2

b. 64 in.2

c. 127 in.2

d. 1,018 in.2