Answer:
1 and 3
Explanation:
The vertical columns (groups) of the periodic table are arranged such that all its elements have the same number of valence electrons. All elements within a certain group thus share similar properties.
The second thesis statement is perfect. It supports the claim and presents main idea.
Acting as a reference point for detecting motion
Answer:
Equation: - 2Li + H2O = Li2O + H2 Uncoated lithium metal reacts with water to form a colorless lithium hydroxide solution and hydrogen gas.
Explanation:
They discovered that *elements* show increase in atomic numbers across the period.
