Solids, liquids and gases and Atomic structure

Question 1

explain how the changes of states of solids, liquids and gases are achieved

Answer 1

• Solid ( melting) ⇒ liquid ( evaporation) ⇒gas
• gas ( condensing) ⇒liquid ( freezing) ⇒ solid
• solid ( sublimation) ⇔ gas

Question 2

describe the changes in arrangement, movement and energy of particles during changes of state

Answer 2

• Solid: still; no energy; all particles touching
• Liquid: Moving to fit space; some energy; all particles touching
• Gas: Moving freely; lots of energy; particles not touching.

Question 3

what does atoms consist of?

Answer 3

• The protons and neutrons in the centre make up the nucleus
• The electrons are orbiting on shells (or orbitals)

Question 4

what is the relative charge and mass for protons, neutrons and electrons?

Answer 4

Relative charge
Proton: +1
Neutron: No charge
Electron: -1

Relative mass
Proton: 1
Neutron: 1
Electron: 0 ( almost)

Question 5

what does the term atomic number stand for?

Answer 5

• Atomic number: number of protons (the same as number of electrons.)

Question 6

what does the term mass number mean?

Answer 6

• Atomic mass: number of protons + neutrons.

Question 7

what does the term isotope mean?

Answer 7

• Isotopes: Atoms of an element with different numbers of neutrons.

Question 8

what does the term relative atomic mass (M_r)mean?

Answer 8

• Relative atomic mass (Ar): the mass of one atom of an element.