[SEC 3] CHAPTER 6 - chemical formulae and equations

Question 1

what are monoatomic elements?

Answer 1

monoatomic elements are elements that exists as uncombined atoms. they are generally unreactive as they have a full valence shell of electrons

Question 2

what are diatomic molecules

Answer 2

diatomic molecules are molecules that exists as two chemically combined atoms

eg. hydrogen, oxygen, nitrogen, fluorine, chlorine, bromine, iodine

Question 3

what are polyatomic molecules

Answer 3

polyatomic molecules are molecules that exists as three or more chemically combined atoms

Question 4

what is the valency or an element?

Answer 4

the valency of an element can be referred to as the number of electrons that must be lost, gained, or shared in order for that element to obtain a stable, noble gas electronic configuration.

Question 5

what is the vallency of an ion?

Answer 5

the valency of an ion is its charge without the sign

Question 6

what are examples of aqueous (aq)?

Answer 6

• DILUTE acids
• alkalis
• soluble salts
• aqueous ammonia
• any substances DISSOLVED in water

Question 7

what are examples of gas (g)?

Answer 7

• common gases: hydrogen, oxygen, carbon dioxide, chlorine, sulfur dioxide, ammonia
• steam or water vapour

Question 8

what are examples of liquids (l)?

Answer 8

• water
• CONCENTRATED acids (eg hydrogen chloride)

Question 9

what are examples of solids (s)?

Answer 9

• most metals except mercury at room temperature
• insoluble compounds/salts (eg. most carbonates)
• most metal oxides (eg. MgO,CuO, ZnO)