Why is it important to dispose of or use elements properly ?

If they aren't disposed of safely, those chemicals can pose a safety hazard to people, animals and the environment. In addition to contaminating soil, hazardous wastes can pollute the air and leach into water sources. ... They are considered hazardous because they also contain lead.

Explanation:

Carrying out investigations in a responsible way can reduce pollution and waste. It can also ensure that natural resources and other materials will be available for future generations. reusing: Glass beakers can be washed and used again.

it would be b. 6co2 + 6h2o --> c6h12o6 + 6o2