How to reduce bias in a scientific investigation

Aluminum reacts with chlorine gas to form aluminum chloride via the following reaction: 2al(s)+3cl2(g)→2alcl3(s) what is the maximum mass of aluminum chloride that can be formed when reacting 32.0 g of aluminum with 37.0 g of chlorine? express your answer to three significant figures and include the appropriate units.

An atom of lithium-7 has an equal number of(1) electrons and neutrons(2) electrons and protons(3) positrons and neutrons(4) positrons and protons

Calculate the mass of carbon in 97.0 g of sucrose c12h22o11