Module 2: Foundations in Chemistry

Question 1

What are the three subatomic particles?

Answer 1

Protons, electrons and Nuetrons

Question 2

What are isotopes?

Answer 2

Isotopes are atoms of the same element with different numbers of neurons.

Question 3

What is the similarity and differences between isotopes?

Answer 3

Similarity
- Isotopes have the same chemical properties because chemical properties are dependednt on electronic configuration and isotopes have the same number of elecrons so they’ll have the same chemical properties.

Differences
- Isotopes have different physical properties. This is because physical properties are dependent on mass number. Isotopes have different numbers of neutrons hence a different mass number.

Question 4

What is relative molecular mass?

Answer 4

Relative molecular mass is the avergae mass of an atom of an element on a scale where an atom of carbon-12 is exactly 12 taking into account it’s naturally existing isotopes.

Question 5

What is relative isotopic mass?

Answer 5

Relative isotopic mass is the average mass of an atom of an element on a scale where an atom of carbon-12 is exactly 12.

Question 6

What is relative molecular mass?

Answer 6

Realtive molecular mass is the average mass of a molecule or a formula unit on a scale where an atom of carbon-12 is exactly 12.

Question 7

What can mass spectrometry be used for?

Answer 7

• Mass Spectra produced by mass spectrometry can be used to work out the relative atomic mass of different elements.
• It can tell us the relative isotopic masses and abundance of different elements.

Question 8

Metal + Acid =

Answer 8

Metal Salt + Hydrogen

Question 9

Metal Oxide + Acid =

Answer 9

Salt + Water

Question 10

Metal Hydroxide + Acid =

Answer 10

Salt + Water

Question 11

Metal Carbonate + Acid =

Answer 11

Metal Salt + Carbon Dioxide + Water

Question 12

What is an Ionic bond?

Answer 12

An ionic bond is an electrostatic force of attraction between oppositively charged ions.

Question 13

Why does Sodium Chloride have a high melting point?

Answer 13

• Sodium chloride has a giant ionic lattice structure so it’s held together by strong electrostatic forces of attraction
• so it has very strong ionic bonds and a lot of energy is required to break the bond.

Question 14

Can Ionic compounds conduct electricity?

Answer 14

• Not when they are solid.
  Ionic compounds do conduct electricity when they are are molten or dissolved in an aqeous solution
• This is beacuse when they are solid, they are ina fixed position dues to the strog ionic bonds but when molten or dissolved, Ionic
  compounds are in a liquid hence they are mobile and they can acrry a charge.

Question 15

Why do ionic compound tend to dissolve in water?

Answer 15

• Water molecules are polar so they are attracted to the charged ions in an ionic compound.
• Water molecules pull the ions away from the lattice and causes it to dissolve

Question 16

What is a Covalent Bond?

Answer 16

A covalent bond is the strong elevtrostatic force of attraction between a shared pair of electrons and the nuclei of the bonded atoms

Question 17

What is electronegativity?

Answer 17

Electronegativity is an atoms ability to attract a bonding pair in a covalent bond.

Question 18

What are ions?

Answer 18

Ions are charged particles that are formed when an atom looses or gains an electron

Question 19

Explain what is meant by the term weighted mean mass.

Answer 19

The mean taking into account the relative abundancies of the isotopes

Question 20

What is an ionic bond?

Answer 20

Ionic bond is the attraction between oppositely charged ions

Question 21

What is a covalent bond?

Answer 21

A covalent bond is a strong electrostatic force of attraction between a shared pair of electrons and the nuclei of the bonded atoms.

Question 22

Why would a giant ionic structure conduct electricity when molten but not when solid?

Answer 22

– When solid the giant ionic structure is held together by strong slectroststic forces of attraction.
– But when they are molten, the ions can move about and carry a charge.

Question 23

Why do ionic componds have a high melting and boiling point?

Answer 23

– The giant ionic lattice are held together by strong electrostatic forces of attraction.
– It takes a load of energy to overcome these forces.

Question 24

What is electronegativity?

Answer 24

Electronegativity is an atoms ability to attract a bonding pair in a covalent bond.