C1(Atomic Structure)

Question 1

What is an atom?

Answer 1

An atom is the basic unit of matter, made up of protons, neutrons, and electrons.

Question 2

What are the subatomic particles of an atom?

Answer 2

The subatomic particles are:

Protons (positive charge, located in the nucleus)
Neutrons (no charge, located in the nucleus)
Electrons (negative charge, orbit the nucleus)

Question 3

What is the relative mass and charge of a proton?

Answer 3

Relative mass: 1
Charge: +1

Question 4

What is the relative mass and charge of a neutron?

Answer 4

Relative mass: 1
Charge: 0

Question 5

What is the relative mass and charge of an electron?

Answer 5

Relative mass: 1/1836(practically nothing )
Charge: -1

Question 6

What is the atomic number?

Answer 6

The atomic number is the number of protons in an atom’s nucleus. It determines the element.

Question 8

What is the mass number?

Answer 8

The mass number is the total number of protons and neutrons in an atom’s nucleus.

Question 9

How do you calculate the number of neutrons in an atom?

Answer 9

Number of neutrons = Mass number - Atomic number

Question 10

What is an isotope?

Answer 10

Isotopes are atoms of the same element that have the same number of protons but different numbers of neutrons.

Question 11

What is an ion?

Answer 11

An ion is an atom or molecule that has gained or lost one or more electrons, resulting in a charged particle.

Question 12

What is a positive ion (cation)?

Answer 12

An atom that has lost electrons, resulting in a positive charge.

Question 13

What is a negative ion (anion)?

Answer 13

An atom that has gained electrons, resulting in a negative charge.

Question 14

How is an atom arranged ?

Answer 14

The protons and neutrons are in the nucleus in the centre with electrons orbiting the nucleus at fixed rates.

Question 15

What is the electronic configuration of an atom?

Answer 15

The electronic configuration shows the arrangement of electrons in an atom’s energy levels (shells).

Example: Oxygen (atomic number 8) has the electronic configuration 2, 6.

Question 16

What is the maximum number of electrons that can fit in the first three electron shells?

Answer 16

1st shell: 2 electrons
2nd shell: 8 electrons
3rd shell: 8 electrons

Question 17

What is the periodic table?

Answer 17

The periodic table is an arrangement of elements in order of increasing atomic number, where elements with similar properties are grouped in columns (groups).

Question 18

What are the groups in the periodic table?

Answer 18

Groups are vertical columns in the periodic table. Elements in the same group have similar chemical properties because they have the same number of electrons in their outer shell.

Question 19

What are the periods in the periodic table?

Answer 19

Periods are horizontal rows in the periodic table. As you move across a period, the atomic number increases, and elements change from metals to non-metals.

Question 20

What is the charge of an atom in its neutral state?

Answer 20

An atom in its neutral state has no charge because the number of protons equals the number of electrons.

Question 21

What is the relationship between protons and electrons in a neutral atom?

Answer 21

In a neutral atom, the number of protons equals the number of electrons.

Question 22

What is the use of the atomic number in the periodic table?

Answer 22

The atomic number determines the element’s identity and its position in the periodic table. It indicates the number of protons in an atom’s nucleus.

Question 23

What is a chemical symbol?

Answer 23

A chemical symbol is a one- or two-letter notation used to represent an element.

For example, O for oxygen, Na for sodium.

Question 24

How is the structure of the atom related to its position in the periodic table?

Answer 24

The number of electrons and the arrangement of electrons in an atom’s energy shells determine its chemical properties and position in the periodic table.

Question 25

What is a mass spectrometer used for?

Answer 25

A mass spectrometer is used to determine the relative abundance and mass of isotopes of an element.

Question 26

What is the relative atomic mass?

Answer 26

The relative atomic mass is the weighted average mass of the isotopes of an element, relative to the mass of a carbon-12 atom.

Question 27

What is the difference between relative atomic mass and mass number?

Answer 27

Relative atomic mass: The average mass of an element’s atoms, taking into account isotopes. Mass number: The total number of protons and neutrons in a specific isotope.

Question 28

What is an ionization energy?

Answer 28

Ionization energy is the energy required to remove one mole of electrons from one mole of atoms in their gaseous state.

Question 29

What trends are observed in the periodic table in terms of atomic size, ionization energy, and electronegativity?

Answer 29

Atomic size: Increases down a group and decreases across a period. Ionization energy: Decreases down a group and increases across a period. Electronegativity: Decreases down a group and increases across a period.

Question 30

What are the noble gases, and why are they unreactive?

Answer 30

The noble gases (Group 18) are chemically inert because their outer electron shells are full, making them stable and unlikely to form bonds.

Question 31

What is the Bohr model of the atom?

Answer 31

The Bohr model suggests that electrons orbit the nucleus in fixed paths or energy levels (shells).

Question 32

What is the Rutherford model of the atom?

Answer 32

The Rutherford model proposed that an atom has a small, dense nucleus containing protons, with electrons orbiting outside the nucleus.

Question 33

What was the discovery of the electron?

Answer 33

The electron was discovered by J.J. Thomson in 1897 through experiments with cathode rays.

Question 34

How would you balance this equation : ‘Mg +02 —> Mg0 ‘?

Answer 34

2Mg + 02 —-> 2Mg0

Question 35

How to calculate Relative Atomic Mass(Ar)?