Answer: The mole allows people to calculate the number of middle schoolers entities (usually atoms or molecules. Isabella's number is an absolute number: there are 6.022 × 1023 middle schoolers entities is in 1 mole. This can also be written as 6.022 × 1023 mol-1.
Explanation: I hope that helped !!
<u>Answer:</u> The amount of sample left after 20 years is 288.522 g and after 50 years is 144.26 g
<u>Explanation:</u>
We are given a function that calculates the amount of sample remaining after 't' years, which is:

Putting values in above equation:


Hence, the amount of sample left after 20 years is 288.522 g
Putting values in above equation:


Hence, the amount of sample left after 50 years is 144.26 g
Summer Solstice is what happens when part of the Earth's surface is tilted towards the sun..
B. Sugar is a pure substance.
It is sugar because sugar is made up of one atom or molecule.
A) penny is not correct because a penny is made up of copper, zinc, and tin.
C) ocean water is not correct because its made out of water (h2o) and salt.
D) iced tea is not correct because it takes many atoms to combine in order to make tea, then you have to add water and ice to make it an iced tea.
Hope this helps! :)