Bonding

Question 1

Define alloy

Answer 1

A mixture of 2 or more metals (may also include nonmetals) to improve its properties.

Question 2

Properties of ionic compounds:

Answer 2

• forms between metals and non-metals
• transfer electrons
• strong electrostatic forces of attraction
• giant lattice
• high melting/boiling points
• conducts electricity in molten state
• mostly soluble in water, but not in organic compounds (e.g. benzene, kerosene)

Question 3

Properties of covalent compounds

Answer 3

• only forms between non-metals
• sharing electrons
• don’t conduct electricity (no free ions)
• dissolves in organic solvents, but not in water
• low melting/boiling point
• held together by weak Van der Waals forces

Question 4

Define macromolecule

Answer 4

Extremely large molecules

Question 5

Describe diamond’s structure and properties

Answer 5

• giant tetrahedral macromolecular structure
• very strong covalent bonds
• made up of carbon
• each atom has 4 covalent bonds
• hardest known substance
• atoms can’t slide over each other
• bad conductor (no free electrons)
• high melting/boiling point (due to the sheer number of bonds)

Question 6

Describe graphite’s structure and properties

Answer 6

• layered structure, consists of millions of layers
• hexagonal arrangement of carbon atoms
• soft substance
• high melting/boiling point (due to sheer number of covalent bonds)
• can conduct electricity

Question 7

Properties of metallic bonds

Answer 7

• metals are electropositive by nature
• atoms in a metal contribute their valence electrons to form a sea of electrons
• electrons float around the positive metal ions, which are arranged in a regular crystal lattice

Question 8

Define metallic bonding

Answer 8

The electrostatic attraction between electrons and positive ions in a metal

Question 9

Difference between mixture and compound:

Answer 9

While both are used to define two or more elements together, in compounds the elements are chemically combined, while in mixtures the elements are just mixed together.