Answer:
a) element
b) compound
c) element
d) compound
Step-by-step explanation:
a) Hydrogen is the chemical element with the symbol H; is the lightest element in the periodic table.
b) Water: It is a substance whose molecule is composed of two atoms of hydrogen and one of oxygen.
⇒ molecular formula: H2O
c) gold: is the chemical element with the symbol Au. It is a very dense, soft and intense yellow metal.
d) sugar: it is a compound whose chemical formula is C12H22O11