C, they could work together to make things from the top down.
Atoms like in chemistry class?
Answer:
334.2× 10²³ molecules
Explanation:
Given data:
Mass of water = 1 Kg ( 1000 g )
Number of molecules = ?
Solution:
Number of moles of water:
Number of moles = mass/ molar mass
Number of moles = 1000 g/ 18 g/mol
Number of moles = 55.5 mol
1 mole contain 6.022× 10²³ molecules
55.5 mol×6.022× 10²³ molecules
334.2× 10²³ molecules
Each isotope of Oxygen has a different number of neutrons
<h3>Further explanation
</h3>
The elements in nature have several types of isotopes
Atomic mass is the average atomic mass of all its isotopes
Isotopes are atoms has the same number of protons but has a different number of neutrons.
So Isotopes are elements that have the same Atomic Number (Proton)
Some of the isotopes of oxygen are:

Each isotope has 8 protons and 8 electrons but has a different number of neutrons
For O-16: number of neutrons = 16-8 = 8
For O-17: number of neutrons = 17-8 = 9
For O-18: number of neutrons = 18-8 = 10