Photosynthesis is the process that plants use to convert light into food. During this process, plants create carbohydrates starting with only carbon dioxide and water. Sunlight is what makes photosynthesis possible.
Answer: Chemical weathering changes the composition of a rock, while physical weathering does not.
Explanation: The definition of a chemical change is a change that cannot be reversed and is caused by a chemical reaction. In this case, a chemical change to a rock would change the composition of the rock while physical changes may change the appearance of the rock, but not the composition.
Answer: Subsistence agriculture.
Explanation: Subsistence agriculture is a type of farming in which farmers cultivate and grow food crops and livestocks to meet their needs and that of their family.
In this type of agriculture, farm products is aimed to survival and it doesn't involve use of large-scale irrigation, chemical fertilizer, or machinery and technology.
Answer: the atomic number (number of protons) order the elements.
Explanation: Each element on the Periodic Table has their own configuration of electrons. In order to have a neutral charge, there is an equal number of protons to electrons. Thus, the atomic number (number of protons) order the elements.
