Atomic structure

Question 1

What are atoms?

Answer 1

Atoms are the smallest part of an element that can exist.

Question 2

How are atoms represented?

Answer 2

Atoms are represented by chemical symbols, which always start with a capital letter.

Examples: Oxygen (O), Helium (He)

Question 3

What is the approximate radius of an atom?

Answer 3

The atomic radius is approximately $1 \times 10^{-10}$ m.

Question 4

What is the radius of an atomic nucleus?

Answer 4

The nucleus radius is less than $1 \times 10^{-4}$ m.

Question 5

What is an element?

Answer 5

An element is a substance composed of only one type of atom.

Question 6

How many unique elements are there?

Answer 6

There are over 100 unique elements.

Question 7

What is a compound?

Answer 7

A compound is a substance containing two or more different elements chemically combined in fixed proportions.

Question 8

What are the key properties of compounds?

Answer 8

Compounds are different from their constituent elements and can only be separated through chemical reactions.

Question 9

Give an example of a compound.

Answer 9

An example of a compound is iron oxide, which is a combination of iron and oxygen.

Question 10

What are subatomic particles?

Answer 10

Subatomic particles include protons, neutrons, and electrons.

Question 11

What is the charge and location of protons?

Answer 11

Protons have a charge of +1 and are located in the nucleus.

Question 12

What is the charge and location of neutrons?

Answer 12

Neutrons have a charge of 0 and are located in the nucleus.

Question 13

What is the charge and relative mass of electrons?

Answer 13

Electrons have a charge of -1 and are located in electron shells with a relative mass of approximately $\frac{1}{2000}$.

Question 14

What is the maximum capacity of the first electron shell?

Answer 14

The first shell can hold a maximum of 2 electrons.

Question 15

What is the maximum capacity of the second electron shell?

Answer 15

The second shell can hold a maximum of 8 electrons.

Question 16

What is the maximum capacity of the third electron shell?

Answer 16

The third shell can hold a maximum of 8 electrons.

Question 17

What is the electron placement strategy?

Answer 17

Electrons are placed starting with the innermost shell and filling shells sequentially.

Example: Carbon (6 electrons) → 2 in first shell, 4 in second shell.

Question 18

What are isotopes?

Answer 18

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

Question 19

Give examples of helium isotopes.

Answer 19

Helium-4 has 2 protons and 2 neutrons, while Helium-3 has 2 protons and 1 neutron.

Question 20

What are ions?

Answer 20

Ions are charged particles formed when an atom gains or loses electrons.

Question 21

How is the charge of an ion determined?

Answer 21

Losing electrons results in a positive ion, while gaining electrons results in a negative ion.

Example: Beryllium ion losing 2 electrons becomes 2+ charged.

Question 22

What is relative atomic mass?

Answer 22

Relative atomic mass is the average mass of an element’s atoms compared to $rac{1}{12}$ of a carbon-12 atom.

Question 23

How is relative atomic mass calculated?

Answer 23

Relative Atomic Mass = $rac{( ext{Percentage}_1 \times ext{Mass}_1) + ( ext{Percentage}_2 \times ext{Mass}_2)}{100}$.

Question 24

Why do decimal values exist in atomic mass?

Answer 24

Decimal values exist due to averaging different isotope masses.

Question 25

What are mixtures?

Answer 25

Mixtures are physical combinations of substances.

Question 26

What is filtration?

Answer 26

Filtration is a technique to separate insoluble solids from liquids.

Question 27

What is simple distillation?

Answer 27

Simple distillation is used to separate a solvent from a solution.

Question 28

What is fractional distillation?

Answer 28

Fractional distillation separates liquids with different boiling points.

Question 29

What is crystallization?

Answer 29

Crystallization is a technique to separate dissolved solids.

Question 30

What is chromatography?

Answer 30

Chromatography is used to separate colored compounds.

Question 31

What was Dalton’s model of the atom?

Answer 31

Dalton’s model depicted the atom as a solid, indivisible sphere.

Question 32

What was Thompson’s Plum Pudding Model?

Answer 32

Thompson’s model represented the atom as a positive charge with embedded electrons.

Question 33

What was Rutherford’s Nuclear Model?

Answer 33

Rutherford’s model described a concentrated positive nucleus with mostly empty space.

Question 34

What is the Electron Shell Model?

Answer 34

The Electron Shell Model describes electrons in fixed shells.

Question 35

What is the Modern Model of the atom?

Answer 35

The Modern Model includes protons, neutrons, and electrons with a precise understanding of their arrangement.

Question 36

What does the structure of the periodic table represent?

Answer 36

Columns represent groups, and rows represent periods.

Question 37

What are group characteristics in the periodic table?

Answer 37

Elements in the same group have the same outer shell electron count.

Example: Group 1 has one outer shell electron.

Question 38

What are period characteristics in the periodic table?

Answer 38

Elements in the same period have the same number of electron shells.