the density increases down the group.
Answer:
After Eris was discovered, they had to decide whether Eris was a planet or not. If they decided it wasn't a planet, they had to also decide whether Pluto should be counted as a planet since Eris and Pluto were quite similar. They were the same size, and they were both part of the Kuiper Belt.
Explanation:
Q1. TI (210/81Thallium)
Q2.
The answers are opposite from each other
Answer:
No, Mercury can actually cause poisoning. That is why other metals, such as Alkaline metals, are used in making batteries
Answer: 480 kJ of energy is released when 3.5 mol of 
reacts.
Explanation:
The balanced chemical reaction is:
Thus it is given that the reaction is exothermic (heat energy is released) as enthalpy change for the reaction is negative.
1 mole of on reacting gives = 137 kJ of energy
Thus 3.5 moles of on reacting gives = 
of energy
Thus 480 kJ of energy is released when 3.5 mol of reacts.
