D. Answer the following questions in brief.
1.
What are elements?
2.
Give the chemical symbol of iron and chlorine.
Write the chemical formulae of the following compounds:
3.
(a) Aluminium oxide
(b) Zinc acetate
Balance the following equation:
Ca(OH), + HCI -CaCl2 + H2O
What does a chemical equation represent?
5.
6.
What are reactants and products in a chemical equation?
7
Give one example of a combination reaction,
Answers
Answer:
1)elements are pure substance,2)iron-fe, chlorine-cl
Explanation:
1.In chemistry an element is a species of atom having the same number of protons in its atomic nuclei. For example, the atomic number of oxygen is 8, so the element oxygen describes all atoms which have 8 protons. In total, 118 elements have been identified.
2.Iron(II) chloride, also known as ferrous chloride, is the chemical compound of formula FeCl2.
3.a) Aluminium oxide =
Al2O3
b) Zinc acetate =
Zn(CH3COO)2
4.dont know
5.A chemical equation is the symbolic representation of a chemical reaction in the form of symbols and formulae, wherein the reactant entities are given on the left-hand side and the product entities on the right-hand side.
6.
The substance(s) to the left of the arrow in a chemical equation are called reactants. A reactant is a substance that is present at the start of a chemical reaction. The substance(s) to the right of the arrow are called products . A product is a substance that is present at the end of a chemical reaction. In the equation above, the zinc and sulfur are the reactants that chemically combine to form the zinc sulfide product.
7.Formation of calcium oxide by the combination elements calcium and oxygen. ... Formation of sulphur trioxide by the combination of sulphur dioxide and oxygen.
marked as brainliest