The Atom- Week 8

Question 1

define the word element

Answer 1

its a chemical substance that can’t be chemically simplified- (e.g. water can be simplified to oxygen and hydrogen, but cant be simplified anymore than that)

Question 2

define the word isotope

Answer 2

they are the same element which may have different number of neutrons or protons

Question 3

Explain what a mole is

Answer 3

a mole of any substance contains the same number of element entities as in 12 grams of pure carbon

Question 4

what are the 2 equations to find the number of moles

Answer 4

number of moles= mass(grams)/formula weight
number of atoms= concentration x volume (n=cv)

Question 5

what is 1l (litre) in dm^3
what is 100 ml in dm^3
what is 300Mm in mol l^-1

Answer 5

1 dm^3
100/1000= 0.1dm^3
0.3 mol l^-1

Question 6

Explain the difference between ionic, covalent and coordinate bonds

Answer 6

*ionic bonds: a chemical link between 2 oppositely charged ions by electrostatic force- between Metals & Non-Metals
*Covalent bonds: a chemical link which is formed when 2 atoms share electron pairs- between Non-Metals
*Co-ordinate bonds: are covalent link between 2 atoms BOTH of them shared electrons come from ONE of the bonding partners

Question 7

Explain what van der Waals forces, dipole-dipole interactions and hydrogen bonds are