Math, asked by nics28cosca, 10 months ago

EXPONENTIAL FUNCTION

the half life of a radio substance is 1,200years and the initial amount of the substance is 300 grams.What amount of substance remains after 1000 years ?

Answers

Answered by adityasingh8635
1

Answer:

(1), where

A

(

t

)

- the amount left after t years;

A

0

- the initial quantity of the substance that will undergo decay;

t

1/2

- the half-life of the decaying quantity.

So, if a problem asks you to calculate an element's half-life, it must provide information about the initial mass, the quantity left after radioactive decay, and the time it took that sample to reach its post-decay value.

Let's say you have a radioactive isotope that undergoes radioactive decay. It started from a mass of 67.0 g and it took 98 years for it to reach 0.01 g. Here's how you would determine its half-life:

Starting from (1), we know that

0.01

=

67.0

(

1

2

)

98.0

t

1/2

0.01

67.0

=

0.000149

=

(

1

2

)

98.0

t

1/2

98.0

t

1/2

=

log

0.5

(

0.000149

)

=

12.7

Therefore, its half-life is

t

1/2

=

98.0

12.7

=

7.72

years

.

So, the initial mass gets halved every 7.72 years.

Sometimes, if the numbers allow it, you can work backwards to determine an element's half-life. Let's say you started with 100 g and ended up with 25 g after 1,000 years.

In this case, since 25 represents 1/4th of 100, two hal-life cycles must have passed in 1,000 years, since

100.0

2

=

50.0

g

after the first

t

1/2

,

50.0

2

=

25.0

g

after another

t

1/2

.

So,

2

t

1/2

=

1000

t

1/2

=

1000

2

=

500

years

.

Answered by harendrasinghtomar99
0

Answer:

please mention question properly what is radio substance

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