Answer:
The atomic radius of calcium is approximately 175
Explanation:
Given that the atomic radius of magnesium = 150 pm
The atomic radius of strontium = 200 pm
Therefore, given that calcium comes in between magnesium and strontium in group 2 of the periodic table, the atomic radius should be half way between the length of the atomic radius of magnesium and strontium, given that the atomic radius is not a fixed quantity
Therefore;
The atomic radius of calcium is approximately given as follows;
The approximate atomic radius (200 + 150)/2 = 175 pm.
Answer:
b
Explanation:
The reaction that is not a displacement reaction from all the options is 
In a displacement reaction, a part of one of the reactants is replaced by another reactant. In single displacement reactions, one of the reactants completely displaces and replaces part of another reactant. In double displacement reaction, cations and anions in the reactants switch partners to form products.
<em>Options a, c, d, and e involves the displacement of a part of one of the reactants by another reactant while option b does not.</em>
Correct option = b.
During this phase Change heat energy is being absorbed by the molecules, and as a result the molecules possess a greater ability to move around and possess higher kinetic energy because of this. The molecules also possess a higher potential energy.
It glow, so light energy go out of the system, exotermic
