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.
Answer:
No they are not the same the are both di
Answer:calcium
Explanation: calcium is an alkaline earth metal,group 2 period 4
Kepler stated three laws of planetary motion.
First law states that the pathway of a planet is an ellipse with the Sun at one of the foci.
Second law states that an imaginary line joining the Sun and a planet sweeps out equal areas during equal lengths of time.
Third law states that the square of the period of the orbit of a planet is directly proportional to the cube of the length of the distance from the Sun.
Therefore, the answer is that Kepler's second law of planetary motion states that planets cover the same area during equal time periods.