A food contains 8 grams of fat and provides 300 calories per gram. What is the percentage of calories obtained from fat in the food

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.