Atoms Flashcards
1
Q
an isotope is determined by the number of
A
protons and neutrons
2
Q
Tearing a paper in half
A
physical change
3
Q
burning a piece of paper
A
chemical change
4
Q
freezing mercury
A
physical change
5
Q
saliva breaking down food
A
chemical change
6
Q
how many neutrons are in 25^MG
A
13
7
Q
how many protons are in a Br- ion
A
35
8
Q
how many electrons are in a As^3- ion
A
36
9
Q
convert 56.04g S8 to moles S8
A
molar mass S8= 256.48g/ mol so 56.04g = 0.2184 mol
10
Q
how many moles is 7.16 x 10^15 particles C2H6
A
7.16 x 10^15 / 6.022 x 10^23=
1.19 x 10^-8 moles
