Atomic Theory

Question 1

Atoms of all elements are made up of three basic particles:

Answer 1

protons (pos), neutrons (0), electrons (neg)

Question 2

where do the electrons orbit? how many can each shell hold + name?

Answer 2

The electrons orbit the nucleus in distinct energy levels called electron shells
1 - K - 2
2 - L - 8
3 - M - 18
4 - N - 32

Question 3

what 3 things does the electron config tell us?

Answer 3

The number of shells used by an atom is the same as the period number
The number of electrons in the outer shell is the same as the group number
Eg Ca 2, 8, 8, 2
It has 4 electron shells and is in Period 4
It has 2 electrons in its outer shell and is in Group 2

Question 4

list the 3 key features of atomic no. and atomic mass.

Answer 4

Atomic number is the number of protons. The Periodic table is arranged in increasing atomic number
Atomic mass (mass number) is the number of protons AND neutrons
Atomic number is also the number of electrons present in a neutral atom