Revision 2E

Identify the species with the following composition:

9 protons, 10 neutrons and 10 electrons.

• F

• Ne

• K

• F^-

• Ca²⁺

Bromine (Br) contains 50.52% of ⁷⁹Br and 49.48% of ⁸¹Br

Calculate the relative atomic mass (A_r) of bromine, accurate to two decimal places.

(a)  

Antimony (Sb) consist of two isotopes: Sb-121 with an isotopic mass of 120.904 and Sb-123 with an isotopic mass of 122.904. The relative atomic mass of antimony is 121.80.

Calculate the percentage abundance

of isotope Sb-121. Give the result to 1 decimal place.

(a)  

State the similarities between a 2s and 3s orbital.

• maximum number of electrons - electron capacity

• size

• shape

• energy levels

Which represents the shape of

an d atomic orbital?

• 
• 
• 
• 
• 

Deduce the maximum number of electrons the fourth shell could hold.

(a)  

The condensed electron configuration

of chromium (Cr) is:

• [Ar] 3d⁴4s²

• [Kr] 3d⁴4s²

• [Ar] 3d⁵4s¹

• [Kr] 3d⁵4s¹

A condensed electron configuration uses the nearest noble gas to represent:

• electrons of the valence shell

• core electrons

• all electrons of an atom

Which electron configuration is correct for the cuprous ion Cu⁺

• 1s²2s²2p⁶3s²3p⁶3d¹⁰4s¹

• 1s²2s²2p⁶3s²3p⁶3d¹⁰

• 1s²2s²2p⁶3s²3p⁶3d⁹4s¹

• 1s²2s²2p⁶3s²3p⁶3d⁹4s¹

Write the full name of HBr_(g) compound:

(a)