1. B. Calcium is a chemical element that can be found as Ca on the periodic table.
2 A. Heterogeneous mixture. Pizza is not uniform and is a variation of cheese, bread, and toppings that aren't mixed completely together.
3. B. Carbon Monoxide, or CO, is a chemical compound, a combination of 2 or more chemical elements.
The five main branches of chemistry are organic chemistry, inorganic chemistry, analytical chemistry, physical chemistry and biochemistry. Chemistry can be further divided into many sub-branches that may fall under more than one of the main branches.
Answer:
Differences: Earth's atmosphere has 5 main layers where as atmospheric layers thins out in each higher layer.
Similarities: They both have multiple layers.
Explanation:
Sorry I only have 1 difference and similarity.