4.1 CHECK and REFLECT

4.1 CHECK and REFLECT

1. Name two properties of matter.
- malleability
- solubility

2. What are the two categories of pure substances in the matter classification tree shown in Figure 4.5 on page 143?
- elements
- compounds

3. How is an element different from a compound?
An element cannot be chemically broken down into any simpler substance, whereas a compound can be as they are elements that have been chemically combined to form one substance.
5. What is the relationship between an element's atomic number and the number of protons in the nucleus of each of its atoms?
An element's atomic number equals the number of protons and neutrons in said atom.

7. What is an ion?
An ion is a positively or negatively charged atom/group of atoms.

13. Suppose you place a kettle on the stove and boil some water. Is the steam that forms evidence of a chemical change or a physical change? Explain.
This is evidence of a physical change because an substance's boiling point is a physical property The substance is not reacting with anything, but simply changing its structure and evaporating.

15. Describe three things about atoms that you did not know before starting work on this section.
I learned that:
- bromine is the only non-metal that is a liquid at room temperature
- neutrons are 1837 times the weight of an electron
- flash point is a chemical property