Answer:
The heart and the blood vessels are a part of the circulatory system. The blood vessels include the arteries, veins and capillaries. The lungs are considered to be the pulmonary part of the circulatory system. The heart is the cardiovascular part of the circulatory system and the vessels are the systemic part of the circulatory system. The main function of the circulatory system is to supply all parts of the body with oxygenated blood and to take away the deoxygenated blood from all parts of the body.
Answer: A) 3.21 g
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side.

We are given:
Mass of iron = 5.58 g
Mass of iron sulphide = 8.79 g
Mass of sulphur = x g
Total mass on reactant side = 5.58 + x
Total mass on product side = 8.79 g
Applying law of conservation of mass, we get:
Hence, the mass of reacting sulfur is 3.21 g.
Where is the link can’t do any work without it
Explanation:
because in the right side there is 2 hydrogen( H) and 2 chloride (Cl) to balace them we have to replace 2.
I think it’s 44.6 J, but I’m not to sure so hoped this helped /:).