Question

1. al + o₂ → al₂o₃

what elements are in the reactants? put the number of atoms of each element by the element name.
____________________
what compounds are in the reactants? ____________________
what elements are in the products? put the number of atoms of each element by the element name.
____________________
what compounds are in the products? ____________________
balanced or unbalanced (circle correct answer)

1. hgo → hg + o₂

what elements are in the reactants? put the number of atoms of each element by the element name.
____________________
what compounds are in the reactants? ____________________
what elements are in the products? put the number of atoms of each element by the element name.
____________________
what compounds are in the products? ____________________
balanced or unbalanced (circle correct answer)

1. h₂ + n₂ → nh₃

what elements are in the reactants? put the number of atoms of each element by the element name.
____________________
what compounds are in the reactants? ____________________
what elements are in the products? put the number of atoms of each element by the element name.
____________________
what compounds are in the products? ____________________
balanced or unbalanced (circle correct answer)

Explanation:

Step1: Analyze reactants of Al + O₂ → Al₂O₃

In reactants, elements are aluminum (Al) with 1 atom and oxygen (O) with 2 atoms. Compounds: O₂ is a molecule of oxygen, Al is an element not a compound.

Step2: Analyze products of Al + O₂ → Al₂O₃

In products, elements are aluminum (2 atoms) and oxygen (3 atoms). Compound is Al₂O₃. Since number of atoms of Al and O are not equal on both sides, it is unbalanced.

Step3: Analyze reactants of HgO → Hg + O₂

In reactants, elements are mercury (Hg) with 1 atom and oxygen (O) with 1 atom. Compound is HgO.

Step4: Analyze products of HgO → Hg + O₂

In products, elements are mercury (1 atom) and oxygen (2 atoms). Compounds: Hg is an element, O₂ is a molecule of oxygen. Since number of oxygen atoms are not equal on both sides, it is unbalanced.

Step5: Analyze reactants of H₂ + N₂ → NH₃

In reactants, elements are hydrogen (H) with 2 atoms and nitrogen (N) with 2 atoms. Compounds: H₂ and N₂ are molecules, not compounds in the sense of multiple - elements.

Step6: Analyze products of H₂ + N₂ → NH₃

In products, elements are hydrogen (3 atoms) and nitrogen (1 atom). Compound is NH₃. Since number of hydrogen and nitrogen atoms are not equal on both sides, it is unbalanced.

Answer:

1. Reactants elements: Al: 1, O: 2; Reactants compounds: O₂; Products elements: Al: 2, O: 3; Products compounds: Al₂O₃; Unbalanced
2. Reactants elements: Hg: 1, O: 1; Reactants compounds: HgO; Products elements: Hg: 1, O: 2; Products compounds: Hg, O₂; Unbalanced
3. Reactants elements: H: 2, N: 2; Reactants compounds: H₂, N₂; Products elements: H: 3, N: 1; Products compounds: NH₃; Unbalanced