Electronic Structure Of The Atom Worksheet (Page 3 of 5) in pdf

Electronic Structure Of The Atom Worksheet Page 3

Complete the following.

Arrangement of Electrons in Energy Levels

Element

Number of Electrons

a) S

b) P

c) Mg

d) Ca

All atoms are neutral. This means that there is always an equal number of positive and negative charges in an atom.

Because protons are positively charged and electrons are negatively charged, there must therefore be an equal number of

electrons and protons in an atom.

An element with 29 electrons per atom must also have ____ protons per atom.

What element is this?

Ions on the other hand have an imbalance of protons and electrons. This means that there are always an unequal number

of electrons to protons. The proton amount is fix however, based on the identity of the element, therefore the number of

electrons must vary in order to account for charge of the atom (ion). If a chloride anion has a charge of –1, then the

number of proton is fix at 17 (the atomic number or the number of protons). The number of electrons therefore must be

18. The 17 positive proton and the 18 negative electrons adds up to –1 net charge. Write out the electron and protons

each of the ions (or atom) below posses.

-3

14 Si

-4

-1

ion or atom

3 Li

15 P

21 Sc

32 Ge

34 Se

No. of p + / e -

10. The electron configuration of an atom is the nomenclature illustrating how electrons are distributed among the various

atomic orbitals. The atom hydrogen has one electron found in the 1s orbital. H has the electron configuration 1s 1 . The

atom carbon has the electron configuration C = 1s 2 2s 2 2p 2 , or it can also be written C = [He]2s 2 2p 2 where [He]

represents the electron configuration 1s 2 . Complete the electron configuration for the following atoms. The filling

sequence is 1s-2s-2p-3s-3p-4s-3d-4p-5s-4d-5p-6s-4f-5d-6p

Atom

electron-configuration

Atom

electron-configuration

1s 2 2s 2 2p 6 3s 2 3p 6 4s2 3d 10 4p 6

i.e. Kr

Electronic Structure Of The Atom Worksheet Page 3