Question

1. sep use evidence cite evidence to show that living systems follow the laws of conservation of mass and energy. 17. ccc energy and matter how is carbon cycled between organisms and the environment?

Explanation:

• For Question 16: In photosynthesis, plants take in carbon dioxide ($CO_2$) and water ($H_2O$) (reactants). Using sunlight (energy), they produce glucose ($C_6H_{12}O_6$) and oxygen ($O_2$) (products). The mass of reactants (calculated as $6CO_2 + 6H_2O$: $6\times(12 + 2\times16)+6\times(2\times1 + 16)=6\times44+6\times18 = 264+108=372$) is equal to the mass of products ($C_6H_{12}O_6+6O_2$: $(6\times12 + 12\times1+6\times16)+6\times(2\times16)=(72 + 12+96)+192=180+192 = 372$). For energy, sunlight (solar energy) is converted into chemical energy stored in glucose. In cellular respiration, organisms break down glucose (chemical energy) into $CO_2$, $H_2O$, and energy (used for cellular work, some lost as heat).
• For Question 17: Plants take in $CO_2$ from the atmosphere during photosynthesis and convert it into organic compounds (like glucose). Herbivores eat plants and incorporate carbon into their bodies. Carnivores eat herbivores (also getting carbon). When organisms respire, they release $CO_2$ back to the atmosphere. Decomposers break down dead organisms, releasing carbon (as $CO_2$ or into soil as organic matter). Fossil fuels (formed from ancient organisms) are burned, releasing $CO_2$ into the atmosphere.

Answer:

• Question 16: In photosynthesis (e.g., $6CO_2 + 6H_2O

ightarrow C_6H_{12}O_6+6O_2$), mass of reactants equals mass of products (calculated as shown above), and solar energy is converted to chemical energy. In cellular respiration (e.g., $C_6H_{12}O_6+6O_2
ightarrow6CO_2 + 6H_2O+$ energy), chemical energy is transformed (some for work, some as heat), showing conservation of energy. Mass is conserved as atoms are rearranged (not created/destroyed).

• Question 17: Carbon is cycled through photosynthesis (plants take in $CO_2$), consumption (herbivores/carnivores get carbon from food), respiration (organisms release $CO_2$), decomposition (releases carbon from dead matter), and fossil - fuel burning (releases stored carbon as $CO_2$).