1. which of the following is a physical change? a. breaking chemical bonds but not changing phase b. a change in phase but no change in molecular structure c. creating a new substance d: enters transfer and change in color 2. which of the following is an example of a chemical change a. mixing of paint colors b. formation of clouds c. metal corrading in salt water d, sugar dissolving in water

B. A change in phase but no change in molecular structure.

C. Metal corroding in salt water.

Explanation:

These are the examples that best correspond with the descriptions. In chemistry, it is important to distinguish between chemical and physical changes. A chemical change is one that produces a new substance. On the other hand, a physical change is one in which the material may change shape or form, but no chemical reactions occur and no new compounds are produced.

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.

all eukaryotic cell have mitochondria : )