Answer:
Explanation:
To solve this problem, we must understand the relationship between mass of a substance and the number of atoms.
Atoms are the smallest indivisible particles of any matter. A substance can be made up of several number of atoms in their space.
The mass of any substance is a function of the amount of atoms its contains.
The mass of a substance is related in chemistry to the amount of atoms its contains using the parameter called the number of moles.
A mole is the amount of substance that contains the Avogadro's number of particles. This number is 6.02 x 10²³ particles. The particles here can be protons, neutrons, electrons, atoms e.t.c.
Now,
Number of moles = 
Molar mass of copper = 63.6g/mole
Number of moles =
= 0.03mole
Since 1 mole of a substance contains 6.02 x 10²³atoms
0.03 mole of copper will contain 0.03 x 6.02 x 10²³atoms
= 1.89 x 10²² atoms
He needs to add 1.89 x 10²² atoms to make 2g of the sample.
Answer:
energy flow and nutrient cycles ( photosynthesis , food webs, decomposition webs) sediment transport and soil formation. the water cycle. reproduction/ regeneration mechanisms.
Answer:
HF - hydrogen bonding
CBr4 - Dispersion
NF3 - Dipole-dipole
Explanation:
Hydrogen bonding occurs when hydrogen is covalently bonded to a highly electronegative atom such as fluorine, chlorine nitrogen, oxygen etc. Hence the dominant intermolecular force in HF is hydrogen bonding.
CBr4 is nonpolar because the molecule is tetrahedral and the individual C-Br dipole moments cancel out leaving the molecule with a zero dipole moment hence the dominant intermolecular force are the dispersion forces.
NF3 has a resultant dipole moment hence the molecules are held together by dipole-dipole interaction.
the mass of 1 mole of phosphorus atoms is approximately 30
g
hope this helps :)