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:
The answer is below!!
Explanation:
Ferns are plants that do not bear flowers. They do not have any seeds as well. In this regard, their mode of reproduction is through spores. Gymnosperms on the other hand have seeds, although they are not put inside an ovary.
Hope I Helped!!
:)
Answer:
stay the same.
Explanation: Period 3 consists of the full 1s, 2s, and 2p electron orbitals, plus the 3s and 3p valence orbitals, which are filled with a total of 8 more electrons as we move from left (Na) to the far right (Ar):
Na: 1s2 2s2 2p6 3s1
Ar: s2 2s2 2p6 3s2 3p6
As we move from left to right, and ignoring the already-filled 1s, 2s, and 2p orbitals, the period three starting and ending elements have the following:
Na: 3s1
Ar: 3s2, 3p6
All the new electrons electrons filled the third energy level (3s and 3p). So the energy level does not change, just the orbitals.
We have a solution of NaOH and H₂CO₃
First, NaOH will dissociate into Na⁺ and OH⁻ ions
The Na⁺ ion will substitute one of the Hydrogen atoms on H₂CO₃ to form NaHCO₃
The H⁺ released from the substitution will bond with the OH⁻ ion to form a water molecule
If there were to be another NaOH molecule, a similar substitution will take place, substituting the second hydrogen from H₂CO₃ as well to form Na₂CO₃