8. Which of the following elements reacts like calcium (Ca) but with less atomic mass?
Potassium (K)
Magnesium (Mg)
Strontium (Sr)
Scandium (Sc)

Magnesium (Mg)

Explanation:

An element with a lower atomic mass than Calcium that has similar chemical property is the element Magnesium (Mg).

This because, elements in the same group or family on the periodic table has similar chemical properties.

Magnesium belongs to the same group as Calcium, other elements are:

     Be  Mg  Ca    Sr  Ba  Ra

The group is made of the alkaline earth metals. They have two valence electrons in their outer shell.

it should be all of them because it asks if you included all of those in your answer

explanation:

shield volcanos are angry and get mad over the smallest things so much that there heads erupt   pahoehoe and a'a lava. a composite volcano is the poller opposite of a shield volcano. its   peaceful thing and knows how to control its emotions.