Question

Define the following :-

(a) Atom

(b) Molecule

(c) Chemical reaction

(d) Compound

(e) Element

(f) Mixture

(g) Displacement Reaction

(h) Neutralisation Reaction

(i) Combination Reaction

(j) Chemical Formula ​

Answer 1

Answer:

1. An atom is the smallest unit of matter that retains all of the chemical properties of an element. ... An atom consists of two regions. The first is the tiny atomic nucleus, which is in the center of the atom and contains positively charged particles called protons and neutral, uncharged, particles called neutrons.
2. Molecule, a group of two or more atoms that form the smallest identifiable unit into which a pure substance can be divided and still retain the composition and chemical properties of that substance.
3. Chemical reaction is a process that involves rearrangement of the molecular or ionic structure of a substance, as distinct from a change in physical form or a nuclear reaction.
4. Compound is something that consists of two or more things or substances combined together.
5. An element is a pure substance consisting only of atoms that all have the same numbers of protons in their atomic nuclei. Unlike chemical compounds, chemical elements cannot be broken down into simpler substances by chemical means.
6. A mixture is a material made up of two or more different substances which are not chemically combined. A mixture is the physical combination of two or more substances in which the identities are retained and are mixed in the form of solutions, suspensions and colloids.
7. A single-displacement reaction, also known as single replacement reaction or exchange reaction, is a chemical reaction in which one element is replaced by another in a compound.
8. Neutralization or neutralisation is a chemical reaction in which acid and a base react quantitatively with each other. In a reaction in water, neutralization results in there being no excess of hydrogen or hydroxide ions present in the solution.
9. A combination reaction is a reaction where two or more elements or compounds combine to form a single compound. Such reactions are represented by equations of the following form: X + Y → XY. The combination of two or more elements to form one compound is called combination reaction.
10. A chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, such as parentheses, dashes, brackets, commas and plus (+) and minus (−) signs.

Hope it helps u.

Answer 2

Answer:

1.The smallest particle of an element

2. A molecule can be defined as the smallest particle of an element.

3. A reaction which take part in every reaction and react with any element.

4. can be broken down into element by chemical reaction

5. cannot be broken down in simpler substance