The half-life is a substance is 375 years. If 70 grams is present now, how much will be present in 500 years?

Use the formula pictured

27.76 grams will be present in 500 years

Step-by-step explanation:

The given formula is , where A is the value of the substance in t years, and is the initial value

∵ The half-life is a substance is 375 years

- Substitute A by and t by 375 to find the value of k

∴

- Divide both sides by

∴

- Insert ㏑ in both sides

∴ ㏑( ) = ㏑ ( )

- Remember ㏑ ( ) = n

∵ ㏑ ( ) = 375 k

∴ ㏑( ) = 375 k

- Divide both sides by 375

∴ k ≈ -0.00185

∴  

∵ 70 grams is present now

- That means the initial value is 70 grams

∴ = 70

∵ The time is 500 years

∴ t = 500

- Substitute the values of and t in the formula

∵

∴ A = 27.76

∴ 27.76 grams will be present in 500 years

a is 8.b is 10.c is 10.5. d is -.5

step-by-step explanation:

just minus the smallest number from the biggest.