Topic 2 - structure and bonding

Question 1

Define ionic bonding

Answer 1

Electrostatic forces of attraction between oppositely charged ions.

Question 2

Properties of a GIANT IONNIC STRUCTURE

Answer 2

regular structure
neat rows of ions
cubic shape
giant repeating pattern

Question 3

How to write ionic formulae

Answer 3

write out elements/molecules with their charges
swap them
move them to subscripts and divide as necessary to get simplest form.

Question 4

Why are most ionic compounds soluble in water?

Answer 4

water is polar and has a strong attraction to the charged ions, which dissociate into it. Water breaks ionic bonds by hydrogen bonding.

Question 5

When can ionic compounds conduct electricity and why?

Answer 5

When molten/dissolved in solution because ions are free to move and carry charge.

Question 6

Why do ionic compounds have really high melting points?

Answer 6

Strong electrostatic forces of attraction require a lot of energy to overcome

Question 7

Why are ionic compounds brittle?

Answer 7

when struck with a hammer, layers of ions slide so cations align with cations and the same with anions. This causes them to repel which in turn breaks the structure.

Question 8

What determines the strength of ionic bonds?

Answer 8

Size of ion: smaller = stronger

charge density: greater = stronger

Question 9

Define isoelectronic

Answer 9

Ions with the same number of electrons / electronic structure. E.g Na+, Mg2+ etc