Question

glucose molecules (shown in the model above) are found in many foods. they contain 6 carbon atoms. when a single glucose molecule is broken down by the body to release energy, which of these will be true?
there will still be 6 carbon atoms, but they will be rearranged into different molecules
there will be less than 6 carbon atoms because the glucose will turn into co₂ which only has one
there will be zero carbon atoms because some will be destroyed by to produce energy
there will be more than 6 carbon atoms because other compounds are necessary for the reaction

Explanation:

According to the law of conservation of mass, atoms are neither created nor destroyed in a chemical reaction. They are just rearranged. Glucose ($C_6H_{12}O_6$) is broken down in cellular respiration. For example, in aerobic respiration, glucose reacts with oxygen ($O_2$). The carbon atoms in glucose are not destroyed. They are incorporated into carbon - dioxide ($CO_2$) molecules. Since there are 6 carbon atoms in one glucose molecule, and each $CO_2$ molecule has 1 carbon atom, the 6 carbon atoms from glucose will be in 6 $CO_2$ molecules (after reaction with oxygen and hydrogen rearrangement). So the number of carbon atoms remains 6, but they are in different molecules.

Answer:

there will still be 6 carbon atoms, but they will be rearranged into different molecules