Amole is the amount of a substance that contains as many particles as the number of atoms in 12 grams of what isotope?

a) boron-12
b) carbon-12
c) calcium-39
d) aluminum-26

B) Carbon-12

Explanation:

In chemistry, a 'mole' is a unit of measurement which reflects the amount or quantity of atoms, molecules, ions or other particles.

A mole is defined as the amount of substance containing as many particles as there are atoms in 12 grams of carbon. In general one mole of a substance is equal to its molar mass expressed in grams.

Therefore:

1 mole = molar mass (g) = 6.023*10²³ particles (Avogadro's number)

a: 45.9 meters

b: 4.29 seconds

step-by-step explanation:

a: h(t)=1/2(-9.8)(3)^2+0(3)+90

h(t)=-4.9(3)^2+90

h(t)=-44.1+90

h(t)=45.9 meters

b: 0=1/2(-9.8)(t^2)+0t+90

0=-4.9t^2+90

-90=-4.9t^2

18.37=t^2

t=4.29 seconds

in the second question, the numbers aren't exact, but they're a close approximation.

its first and third is your answer i did the qustion the fourth isnt right