NCEA Level 1 Chemistry Study Notes

1. Atomic Structure

Atoms: Basic unit of matter, consisting of protons, neutrons, and electrons.
Elements: Pure substances made of one type of atom, listed in the periodic table.
Atomic Number: Number of protons in the nucleus, defines the element.
Mass Number: Total number of protons and neutrons.

2. The Periodic Table

Groups: Vertical columns, elements share similar properties (e.g., Group 1 - alkali metals).
Periods: Horizontal rows, indicate the number of electron shells.
Metals vs. Nonmetals: Metals are to the left, nonmetals to the right; metalloids are on the staircase line.

3. Chemical Bonds

Ionic Bonds: Formed by the transfer of electrons from one atom to another, resulting in charged ions.
Covalent Bonds: Formed by the sharing of electrons between atoms.
Metallic Bonds: Involves a 'sea of electrons' shared among metal atoms.

4. Chemical Reactions

Reactants: Substances that undergo change during a reaction.
Products: New substances formed as a result of a chemical reaction.
Types of Reactions:
- Combination: Two or more substances combine to form one.
- Decomposition: A single compound breaks down into two or more products.
- Displacement: One element replaces another in a compound.
- Combustion: A substance reacts with oxygen, releasing energy.

5. Acids and Bases

Acids: Substances that release hydrogen ions (H+) in solution (e.g., hydrochloric acid).
Bases: Substances that release hydroxide ions (OH-) in solution (e.g., sodium hydroxide).
pH Scale: Measures acidity (0-7) and alkalinity (7-14), with 7 being neutral.
Neutralization: Reaction between an acid and a base to produce water and a salt.

6. Stoichiometry

Moles: A unit that measures the amount of substance; 1 mole = 6.022 x 10²³ particles.
Balanced Equations: Represent the conservation of mass; same number of each type of atom on both sides.
Calculating Mass: Use molar mass to convert between moles and grams.

7. States of Matter

Solid: Fixed shape and volume; particles packed closely together.
Liquid: Fixed volume but takes the shape of its container; particles are close but can move.
Gas: No fixed shape or volume; particles are far apart and move freely.

8. Solutions and Concentrations

Solvent: The substance that dissolves the solute (usually in larger quantity).
Solute: The substance being dissolved (in smaller quantity).
Concentration: Amount of solute in a given volume of solvent, often expressed in mol/L.

9. Safety in the Laboratory

Personal Protective Equipment (PPE): Use gloves, goggles, and lab coats.
Chemical Safety: Read labels, understand hazards, and know how to handle spills and accidents.

These notes provide a concise overview of key concepts in NCEA Level 1 Chemistry, covering fundamental principles and essential knowledge needed for study and assessment.

Atomic Structure

Atoms are the fundamental units of matter composed of protons, neutrons, and electrons.
Elements are pure substances consisting of just one type of atom, organized in the periodic table.
The atomic number indicates the number of protons and uniquely identifies each element.
The mass number is the sum of protons and neutrons in an atom's nucleus.

The Periodic Table

Groups are vertical columns in the periodic table; elements in the same group exhibit similar chemical properties.
Periods are horizontal rows that denote the number of electron shells in the elements.
Metals are located on the left side of the periodic table, whereas nonmetals are found on the right; metalloids are positioned along the dividing staircase.

Chemical Bonds

Ionic bonds occur through the transfer of electrons, forming charged ions with opposite charges.
Covalent bonds result from the sharing of electrons between two or more atoms.
Metallic bonds involve the delocalization of electrons, creating a "sea of electrons" that holds metal atoms together.

Chemical Reactions

Reactants are the starting materials that undergo transformation during a chemical reaction.
Products are the new substances produced after a chemical reaction has occurred.
Key types of chemical reactions include:
- Combination reactions where multiple substances merge to create a single new substance.
- Decomposition reactions where a single compound breaks down into two or more products.
- Displacement reactions where one element takes the place of another in a compound.
- Combustion reactions which involve a substance reacting with oxygen to release energy.

Acids and Bases

Acids are substances that donate hydrogen ions (H+) in an aqueous solution, with hydrochloric acid as a common example.
Bases release hydroxide ions (OH-) in solution, such as sodium hydroxide.
The pH scale ranges from 0 (acidic) to 14 (alkaline), with 7 being neutral.
Neutralization is the chemical reaction between an acid and a base that produces water and salt.

Stoichiometry

Moles serve as a unit for measuring the amount of substance; one mole contains approximately 6.022 x 10²³ particles.
Balanced chemical equations reflect the law of conservation of mass, maintaining equal numbers of each atom type on both sides of the equation.
Mass calculations involve using molar mass to relate moles to grams.

States of Matter

Solids possess a fixed shape and volume, with particles tightly packed in a defined arrangement.
Liquids maintain a fixed volume but adapt to the shape of their container; particles are close but able to move around.
Gases do not have a set shape or volume, with particles widely spaced and moving freely.

Solutions and Concentrations

The solvent is the substance that facilitates the dissolution of the solute, typically present in greater quantities.
The solute is the substance being dissolved, usually in lesser amounts.
Concentration is quantified as the amount of solute present in a specified volume of solvent, often represented in moles per liter (mol/L).

Safety in the Laboratory

Personal Protective Equipment (PPE) includes gloves, goggles, and lab coats to safeguard against chemicals.
Chemical safety requires awareness of product labels, hazard identification, and protocols for spill management and emergency responses.