were new substances formed when heat was applied to (a)sulfur and (b)sugar?

Answer 1

No new substances will be formed when applying heat to sulfur. It will turn into a liquid sulfur, and finally a gaseous sulfur. Sugar is different. Applying heat to sucrose (C12H22O11) will form water vapor (11H2O) and elemental carbon (12C).

Answer 2

More than you ever wanted to know about Sulfur:
Ordinary sulfur is a yellow solid substance which forms crystals with orthorhombic symmetry. It is insoluble in water, but can be dissolved in carbon disulfide, carbon tetrachloride, and similar non-polar solvents.

This form of sulfur melts at 112.8°C to form a straw colored liquid, which then recrystalizes upon cooling to a monoclinic crystalline form.

Sulfur liquid at temperatures around 120°C is a straw-colored liquid of low viscosity, As the liquid is heated, it gradually darkens in color and becomes more viscous. At about 200°C it is a dark red mass which cannot be poured out of its container. Most substances decrease in viscosity with increasing temperature. Sulfur is unique in that it forms long chain molecules with increasing temperature, called gamma sulfur.

Sulfur has a nominal density of 2 gm/cm3, but in its rhombic crystalline form it has a density of 5.4 gm/cm3.