3. Reactions of Metals

Question 1

What are the physical properties of metals?

Answer 1

• lustrous
• malleable
• ductile
• good conductors of heat
• good conductors of electricity
• generally high density
• have a range of melting points but mainly high
• are often hard

Question 2

What does delocalised mean?

Answer 2

Delocalised describes electrons that are not bound to any one atom but are free to move throughout a lattice

Question 3

What is the metallic bonding model?

Answer 3

Metals have low electronegativity (lose electrons easily to get noble gas configurations) - metal atoms will lose electrons, these are called delocalised electrons, and they form a ‘sea’. The cations will be attracted to the sea of electrons in all directions, this results in the cations being held very tightly together.

Question 4

What is metallic bonding?

Answer 4

Metallic bonding is positively charged metal cations arranged in a lattice with delocalised valence electrons being able to flow around them.

Question 5

Explain metal characteristics in relation to the metallic bonding model?

Answer 5

• Lustrous (looks shiny) - sea of electrons reflects light
• Malleable (able to be hammered and bent) and ductile (drawn into wires) - the forces between the cations and the delocalised electrons are non-directional, the cations can be pushed around a bit without breaking the bonds
• Electrical conductivity and heat conductivity - sea of electrons, electrons will flow when a current is passed through (the delocalised electrons moving is the actual current) and the delocalised electrons can vibrate easily when heat is applied.
• High density - cations are packed together tightly
• High melting point - metallic bonds are strong (not as strong as covalent bonds)

Question 6

In what direction do metals become more reactive?

Answer 6

Left and down the periodic tableAs atoms that have more electron shells find it more difficult to hold their valence electrons, and atoms that have only one valence electron in the outer shell lose electrons easier than those with more

Question 7

How do group 1 metals react with water?

Answer 7

G1 metal + water –> g1 metal hydroxide + hydrogen gas

potassium + water –> potassium hydroxide + hydrogen gas

Question 8

How do group 2 metals react with water (steam)?

Answer 8

G2 metal + steam –> g2 metal hydroxide + hydrogen gas

magnesium + steam –> magnesium hydroxide + hydrogen gas

Question 9

How does metal react with acid?

Answer 9

Reactive metal + acid –> metal salt + hydrogen gas

magnesium + HCl –> magnesium chloride + hydrogen gas

Question 10

How do metals react with oxygen?

Answer 10

Reactive metal + oxygen –> metal oxide

magnesium + oxygen –> magnesium oxide