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Question 1

What is the structure of an atom?

Answer 1

An atom consists of a nucleus surrounded by electrons in electron shells.

The nucleus contains protons and neutrons.

Question 2

Describe electron shells and their energy levels.

Answer 2

Electron shells are regions around the nucleus where electrons are located, with shells closer to the nucleus having lower energy, and ones further having higher energy levels.

The energy level increases with distance from the nucleus.

Question 3

How do you read and write electron configurations of atoms?

Answer 3

Electron configurations are written using the number of electrons in each shell, following the order of filling.
For example: Cl - 2,8,7

For example, the electron configuration of carbon is 1s² 2s² 2p².

Question 4

What information can be assumed from group and period numbers?

Answer 4

Group numbers indicate the number of valence electrons, and period numbers indicate the number of electron shells.

For example, Group 1 elements have one valence electron.

Question 5

Recognize the groups in the periodic table.

Answer 5

1. Alkali metals
2. Alkaline earth metals
3. Transition metals
4. Post transition metals
5. Metalloids
6. Other non-metals
7. Halogens
8. Noble gases

Each group has distinct properties.

Question 6

Property of Alkali metals

Answer 6

High reactivity, shiny

For example, alkali metals are highly reactive with water.

Question 7

Property of Alkali Earth metals

Answer 7

Good conductor of heat and silvery-shiny

Question 8

Property of Transition metals

Answer 8

High melting and boiling points, malleable

Question 9

Property of Post-transition Metals

Answer 9

Soft or brittle

Question 10

Property of Metalloids

Answer 10

Shiny and behaves like a weak non-metal

Question 11

Property of Halogen

Answer 11

Highly reactive compared to noble gasses and electronegativity

Question 12

Property of Noble Gasses

Answer 12

Unreactive as it is stable, and colored

Question 13

What is the octet rule?

Answer 13

The octet rule states that atoms tend to gain, lose, or share electrons to achieve a full outer shell of eight electrons.

This is particularly relevant for main group elements.

Question 14

Where are electrons located?

Answer 14

Electrons are located in electron shells surrounding the nucleus.

These shells hold different numbers of electrons based on their energy levels.

Question 15

How are ions formed?

Answer 15

Ions are formed when atoms gain or lose electrons, resulting in a net charge.

Cations are positively charged, while anions are negatively charged.

Question 16

Explain how ionic bonds are formed

Answer 16

Ionic bonds form when cations and anions attract each other due to opposite charges, and the cation donates its valence electrson to the anion to both become stable.
E.g. Mg and O both require 2 electrons to be lost and gained so they combine and transfer to each other.

This typically occurs between metals and nonmetals.

Question 17

How does ionic bonding involve the transfer of electrons between atoms?

Answer 17

Ionic bonding involves one atom donating electrons to another, resulting in the formation of ions.

For example, sodium donates an electron to chlorine.

Question 18

What is the structure of ionic compounds?

Answer 18

Ionic compounds have a regular lattice structure formed by alternating cations and anions.

This structure contributes to their high melting points.

Question 19

How do you determine the chemical formula of ionic compounds using the name?

Answer 19

Identify cation’s name and charge. Then, identify anion’s name and charge. Combine both.
E.g. Sodium and Chlorine becomes NaCl

For example, NaCl consists of Na⁺ and Cl⁻.

Question 20

Compare the reactivity of various metals.

Answer 20

Reactivity varies based on position in the periodic table; alkali metals are most reactive, while noble metals are least reactive.

Reactivity can be tested through reactions with water or acids.

Question 21

Explain the reactivity of metals based on their location on the periodic table.

Answer 21

Metals reactivity increases down a group and decreases across a period.

This is due to the increasing atomic size and decreasing electronegativity.

Question 22

Describe covalent molecular bonding.

Answer 22

Covalent bonding involves the sharing of electron pairs between atoms. Can only share a maximum of three pairs of electrons

This typically occurs between nonmetals.

Question 23

List common properties of covalent molecules.

Answer 23

• Lower melting and boiling points
• Poor electrical conductivity
• Often exist as gases or liquids at room temperature

These properties contrast with ionic compounds.

Question 24

What type of bonding is present in amino acids?

Answer 24

Amino acids primarily exhibit covalent bonding.

Peptide bonds form between amino acids during protein synthesis.

Question 25

Identify the elements that make up the 20 essential amino acids.

Answer 25

The essential amino acids consist of carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur. Remember CHONS ## Footnote These elements form the backbone of amino acids.

Question 26

How do amino acids link together to form proteins?

Answer 26

Amino acids link through peptide bonds formed during dehydration synthesis. ## Footnote This process creates polypeptide chains.

Question 27

Define polyatomic ions.

Answer 27

Polyatomic ions are ions composed of two or more atoms bonded together, carrying a net charge. ## Footnote Examples include sulfate (SO₄²⁻) and ammonium (NH₄⁺).

Question 28

Properties of metals

Answer 28

Shiny, very dense, malleable, and having high melting points

Question 29

Describe how atoms gain energy to be excited

Answer 29

Atoms absorb energy, such as light or heat. This causes them to be excited and jump to higher energy levels.

Question 30

Describe how atoms lose energy to become stable

Answer 30

Atoms become stable by forming chemical bonds or through the emission of radiation