Strontium-90 has a half-life of 28.8 years. If you start with a 300-gram sample of strontium-90,
how much will be left after 1440 years?

 2.66 × 10⁻¹³

Step-by-step explanation:

First, use the decay formula     where

A is the final amount (amount left)A₀ is the initial amount (amount you started with)k is the rate of decay (you need to solve for this)t is the time

Given:

A = 1/2(300) = 150A₀ = 300k = unknownt = 28.8

Next, input the k-value and the new t-value to solve for A.

A = unknownA₀ = 300k = -0.0240676t = 1440

The lateral side of a triangular pyramid is a triangle. in order to increase the lateral surface area, the slant height and the height should be altered

4should be the last one n=4