to build an electrically neutral model of a with an atomic mass of 7.
select the correct statement(s) about the lithium (li) atom.
lithium (li) is found in the same group as hydrogen (h) and has one valence electron.
lithium (li) has three protons and an atomic number of 3.
lithium (li) is found in the same group as beryllium (be) and has two electron shells or energy levels.
lithium (li) is found in the same period as helium (he) and has two electron shells or energy levels.
lithium (li) is found in the same period as beryllium (be) and has two electron shells or energy levels.

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# Brief Explanations:
- **First statement**: Lithium ($Li$) is in Group 1 (alkali metals), hydrogen ($H$) is in Group 1 but is a non - metal. Lithium has 1 valence electron. This statement is correct.
- **Second statement**: The atomic number of an element is equal to the number of protons. For lithium ($Li$), atomic number $Z = 3$, so it has 3 protons. This statement is correct.
- **Third statement**: Lithium ($Li$) is in Group 1, beryllium ($Be$) is in Group 2. So this statement is incorrect.
- **Fourth statement**: Lithium ($Li$) is in Period 2, helium ($He$) is in Period 1. So this statement is incorrect.
- **Fifth statement**: Lithium ($Li$) and beryllium ($Be$) are both in Period 2. The number of electron shells (energy levels) is equal to the period number. So lithium ($Li$) has 2 electron shells. This statement is correct.

# Answer:
- Lithium ($Li$) is found in the same group as hydrogen ($H$) and has one valence electron.
- Lithium ($Li$) has three protons and an atomic number of 3.
- Lithium ($Li$) is found in the same period as beryllium ($Be$) and has two electron shells or energy levels.

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