Answer: 1. Block
2. True ( I'm unsure. He arranged it according to mass, but he is credited for the periodic table)
3. Noble gasses
4. technetium
5. Alkaline earth metals
6. Number of protons
7. False
8. Not true: generally decreases as atomic number increases within a period
9. Argon
10. Four
11. False
12. False
Explanation:
Answer:
D atom
Explanation:
The smallest particle of a substance that retains the chemical and physical properties of the substance and is composed of two or more atoms
Answer:
<em>Valency is the combining power of an element. Elements in the same group of the periodic table have the same valency. The valency of an element is related to how many electrons are in the outer shell. The noble gases have the valency 0 as they do not usually combine with other elements.</em>
Explanation:
HOPE IT HELPS
First one is reactants and then second one is products
