Help ASAP PLEASE
1-Name the elements in gp1.
2-Why are these elements placed in gp1?
3-Mention the trends in atomic size, atomic number, mass number, reactivity, boiling & melting points.

H - hydrogen

Li - lithium

Na - sodium

K - potassium

Rb - rubidium

Cs - cesium

Fr - francium

These elements are in the first main group because they only have one valence electron, which is located in an s orbital.

The atomic size increases from H to Fr.

The ordinal number increases from H to Fr.

The mass number increases from H to Fr.

The reactivity increases from H to Fr.

The melting point drops from Li to Fr.

The boiling point drops from Li to Fr.

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