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Do you want the estimated answer or the exact answer?
Answer:
Explanation:
An atom is the smallest unit of an element that can take part in a chemical reaction. Atoms (and there corresponding symbols) mentioned in the question are
Lithium ⇒ Li
Carbon ⇒ C
Nitrogen ⇒ N
Potassium ⇒ K
Oxygen ⇒ O
Iron ⇒ Fe
Chlorine ⇒ Cl
A compound is substance that contains two or more atoms that are chemically combined and can be represented with a chemical formula. The compounds (and there corresponding formula) mentioned in the question are
Water ⇒ H₂O
Edible salt (sodium chloride) ⇒ NaCl
Chalk (calcium carbonate) ⇒ CaCO₃
Lime (calcium oxide) ⇒ CaO
Iodides (such as sodium iodide and potassium iodide) ⇒ NaI and KI respectively
Answer: 72 grams of 
are needed to completely burn 19.7 g 
Explanation:
According to avogadro's law, 1 mole of every substance weighs equal to molecular mass and contains avogadro's number 
of particles.
To calculate the number of moles, we use the equation:
Putting in the values we get:
According to stoichiometry:
1 mole of 
requires 5 moles of oxygen
0.45 moles of require= 
moles of oxygen
Mass of 
72 grams of are needed to completely burn 19.7 g
All of th above support the heliocentric theory.
