They flow and can take the shape of their container
Positive ions are atoms that have lost an electron from its outtermost shell. It is positive because electrons are negative and the loss of something negative makes it a bit more positive.
A negative ion is larger than its original atom because it's gained an electron.
The more electrons an atomic has on its electron cloud, the bigger the atom.
Hopefully I didn't confuse you, good luck. ♡
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.
Elements are made of only one kind of atom. The molecule is made up of two or more kinds of atoms. There is no physical change that can separate the compounds into more than one kind of substance. This makes a compound a pure substance.
