Oxygen is the second. The first is nitrogen which makes up 78% of air. Oxygen makes up 21% of air.
Answer:
A car stopped at the top of the hill
Explanation:
It's potenial energy because, the car could go down the hill and create kinetic energy. Hope this helps! Please give me brainly it is correct!
You can see the periodic table one by one.
Pb(NO3)2 = PbN2O6
So there are
1Pb
2N
6O
and so you find the molecular mass from the periodic table and add all the numbers
Molacular mass of
Pb = 207
N = 14
O = 16
multiply it with the number of atoms
1Pb = 207 × 1 = 207
2N = 14 × 2 = 28
6O = 16 × 6 = 96
Molecular mass total = 207 + 28 + 96 = <u>3</u><u>3</u><u>1</u>
So the molecular mass is 331.
The answer is going to be the first option. What they found out is that atoms are made up of mostly space, but there is a positively charged mass in the center of the atom.
Dissolve means a mixture of chemicals combine.
Example: salt and water you put salt in water stir and the salt dissolve
