If an element A has 3 shells and has 3 valence electrons, write formulas for the following: a. Nitrate of A

b. Chloride of A

c. Oxide of A

Electron configuration

an element A has 3 shells and has 3 valence electrons

so electron configuration of A: 1s², 2s², 2p⁶, 3s², 3p¹

will tend to lose 3 electron to form a cation: A³⁺

a. Nitrate of A

A(NO₃)₃

b. Chloride of A

ACl₃

c. Oxide of A

A₂O₃

Explanation:

Density is defined as the mass of the substance present in the unit volume of the substance.

When a substance is immersed in the liquid with density greater than that of the substance. Then the substance will float on the liquid.When a substance is immersed in the liquid with density lower than that of the substance. Then the substance will sink in the liquid

So, when the rock is immersed in the water the it sank because the density if the rock is greater than the density of water.

Where as wooden block float in the water because the density of the wooden block is less then the density of the water.