Krypton-85 has a half-life of 10.76 years. It decays into rubidium-85. Suppose a sample contains 4 atoms of krypton-85 and 12 atoms of rubidium-85.
About how old is the sample?
A. 10.76 years
B. 21.52 years
C. 43.04 years
D. 32.28 years

gas and liquid

part 1: which substance has a higher solubility?

a

smallest amount left undissolved atall temps in table shown most has dissolved high sol'by

the best answer for these questions would be:

1.            c. is smaller

2.            d) concrete operational

3.            b) interaction with the environment – the children interact with their environment can them learn more.

4.            a) parents who reason openly with children can limit a child’s cognitive ability.