Both Ca and Sr are in Group 2 of the Periodic Table, with Sr below Ca (see image)..
<em>Ionization energies
</em>
They are both metals, so they have relatively <em>low ionization energies</em>.
Sr is below Ca in the Group, so Sr has the lower ionization energy.
<em>Electron configurations
</em>
Their electron configurations both end in <em>ns²</em>.
For example, the electron configuration of Ca is [Kr]<em>4s²</em> and that of Sr is [Kr]<em>5s²</em>.
<em>Physical chsrscteristics:
</em>
- metallic lustre
- malleable
- ductile
- good conductors of heat and electricity
<em>Chemical characteristics</em>
Both metals react with
• <em>Hydrogen</em> to form hydrides: M + H₂ ⟶ MH₂
• <em>Oxygen</em> to form oxides: 2M + O₂ ⟶ 2MO
• <em>Nitrogen</em> to form nitrides: 3M + N₂ ⟶ M₃N₂
• <em>Halogens</em> to form halides: M + X₂ ⟶ MX₂
• <em>Water</em> to displace hydrogen: M + 2H₂O ⟶ M(OH)₂ + H₂