Write either the name of the chemical formula or the formula for the chemical name.

1. sio2
2. lead(ii) sulfide
3. mgcl2

1.  Silicon dioxide

2.

3. Magnesium chloride

Explanation: For naming binary covalent compounds like The name of the non-metal present on the left in the periodic table is written followed by the name the other non-metal by its elemental name ending with -ide. Use the prefix mono-, di-, tri-.... to indicate the number of the other non metal in the molecule.

For binary ionic compounds, like lead sulfide and , The cation is named first, and then the anion is named. Cations are named by their elemental name and anions are named by their elemental name and ends with "-ide"  without any prefix or suffix.

the density of gold = 19.3 g/cm3

the relation between density and mass and volume is

density = mass / volume

given :

mass of gold = 13 g

density = 13g / volume = 19.3

volume = 13 /19.3 = 0.67 cm^3

thus volume of gold nugget = 0.67 cm^3