atomic structure

Question 1

Atoms consist of…

Answer 1

an extremely small, positively charged nucleus surrounded by negatively charged electrons.

Question 2

What is the charge and mass of a proton, neutron and electron?

Answer 2

Proton: charge = +1, mass = +1
Neutron: charge = 0, mass +1
Electron: charge = -1, mass = 0

Question 3

How are atoms electrically neutral?

Answer 3

They contain an equal number of protons & electrons so the positive & negative charges “cancel out”.

Question 4

Define an isotope.

Answer 4

Atoms of the same element with the same number of protons but different number of neutrons in the nucleus.

Question 5

What’s the formula for relative atomic mass?

Answer 5

(% of isotope A x mass of isotope A) + (% of isotope B x mass of isotope B)/100

Question 6

How is the periodic table arranged?

Answer 6

• in order of increasing atomic number in periods.
• elements with similar properties placed in same groups.