Atomic Structure. Science - Atomic Structure.

What is the atomic number of an element whose electronic configuration is 2, 8, 1?

An atom differs from its ion in ………………

Isotopes exist because atoms of the same element can have different numbers of –

Metals form ……………..

Whatis the valency of carbon?

The atomic theory was first proposed by ……………….

Maximum number of electrons that can be present in N shell is ……………….

Atoms which carry positive or negative charges are called ……………….

All non – metals will have ……………… electrons in the outermost orbit of their atoms.

Atoms of all metals will have …………….. electrons in their outermost orbit.

When an atom gains an electron it has more number of electrons and thus it carries positive charge.

Helium has two electrons in the outermost orbit and so it is chemically inert.

The combining capacity of an atom is called valency.

An atom has a number of orbits and each orbit has protons.

In television tube, Cathode rays are deflected by magnetic fields.

Assertion : Helium has four electrons in the outermost orbit.
Reason : Neon has eight electron in the outermost orbit.

Write the names for the following compounds,

1. Aluminium sulphate
2. Silver nitrate.

Name the four laws of chemical combinations.

Draw a diagram to show the electronic configuration of chlorine atom.

Draw a diagram to show the electronic configuration of sodium atom.

What is a balanced chemical equation?

Ruthresh, Hari, Kanishka, and Thahera collected different samples of water from a well, a pond, a river, and underground water. All these samples were sent to a testing laboratory. The test result showed the ratio of hydrogen to oxygen as 1:8.
a. What conclusion would you draw from the above experiment?
b. Which law of chemical combination does it obey?

Write the chemical formula for the following compounds
a. Aluminium sulphate
b. Silver nitrate
c. Magnesium oxide
d. Barium chloride

Write the properties of anode rays.

Write the main postulates of Dalton’s Atomic theory.

Explain the properties of Cathode rays.

Explain the construction of cathode Ray Tube (CRT) with a diagram.

Describe an experiment to prove that during a chemical charge, the total mass of matter remains the same.

Crossword puzzle :
Across:
1. The particles that build up an atom.
3. The arrangement of electrons in a succession of energy levels or shells.
5. An electrically neutral sub atomic particle that is part of the nucleus of an atom.
6. A whole number that represents the ability of an atom or a group of atoms to combine with other atoms or group of atoms.
7. The number of protons in the nucleus of an atom.
8. The smallest unit of an element that maintains the properties of an element.
A sub – atomic particle that has a positive electric charge.
Down:
2. A substance that cannot be broken down into simpler substance by chemical means.
4. The total number of protons and neutrons present in the nucleus of an atom.
9. An ion that has a negative charge.
11 A sub – atomic particle with a negative electric charge.
12. Positively charged ions.

State the law of conservation of mass.