Answer:
The identity of an atom is determined my the number of <u>protons</u>. This is the <u>atomic number</u>.
The particle(s) found inside the nucleus are called <u>protons and neutrons</u>. Their combined mass is referred to as <u>the mass number</u>.
Isotopes have the same number of <u>protons</u>, but different number of <u>neutrons</u>.
<span>pb(no3)2 + 2 nacl → pbcl2 + 2nano3</span>
Endothermic reactions and Exothermic reaction are never the same.
They are both different.
Definitions
<span><span>Endothermic:- reactions that take in energy. For example:- electrolysis, thermal decomposition and the reaction between ethanic acid and sodium carbonate.
</span><span>Exothermic:- reactions that transfer energy to the surroundings. For example:- burning, neutralisation and the reaction between water and calcium oxide.</span></span>