1.1- The particulate Nature of Matter

What is an element?

An element is a pure substance made up of only one type of atom that cannot be broken down into smaller substances by chemical means. Each element has its own unique properties.

What are compounds?

When atoms of different elements combine in fixed ratios and creates a substance with different chemical properties.

Chemical formula of a compound

Shows the types of atoms present and the fixed ratio in which they are chemically combined

What is a mixture?

A combination of two or more elements or compounds that are not chemically bonded together and can be separated by physical means

What are the two types of mixture?

Homogenous and heterogenous mixtures

Homogenous mixture

A mixture where components are uniformly distributed in a single phase, resulting in the same composition and properties throughout the sample

Heterogenous mixture

A mixture where components are not uniformly distributed and consists of two or more different phases with different properties.

What do separation techniques do?

Methods used to isolate substances in a mixture

What are the different separation techniques?

Solvation, filtration, recrystallization, evaporation, distillation, chromatography

Solvation

A process in which a solvent is used to dissolve a solute, leaving the insoluble substance behind to be easily filtered out.

Filtration

Technique used to separate an insoluble solid from a liquid by passing the liquid through a porous barrier like filter paper. the solid is left as residue while the liquid that is able to pass through is called the filtrate.

Evaporation

A process where the liquid turns into vapor by heating the mixture, and it leaves the solid behind.

Distillation

A process used to separate components in a mixture in which the components have different boiling points. The mixture is heated until the component with the lower boiling point vaporizes. The vapor is then cooled by a condenser, causing it to return to a liquid form and be collected separteley

Chromatography

Technique that separates the components of a mixture based on their different affinities for a mobile and stationary phase.

Mobile phase

The fluid, either liquid or gas, that moves through the chromatographic system and carries the samples.

Stationary phase

The solid or supported liquid material that remains fixed in place. It interacts with and slows down the components of the mixture as they pass over it

What are the three physical states in which matter can exist?

Solid, liquid and gas

Solid

state of matter that has a fixed volume and shape, cannot be compressed, and particles vibrate in fixed positions

Liquid

A state of matter with a fixed volume but no fixed shape cannot be compressed, and their praticles vibrate, rotate, and translate.

Gas

Dot have a fixed volume nor shape, can be compressed and their particles can vibrate, rotate and translate freely

What is temperature? What is it measured in?

A measure of the average kinetic energy of the particles in a substance. Its SI unit is kelvin, which equals to degrees Celsius plus 273

What is a phase change?

A physical change of matter from one state to another due to changes in temperature and/or pressure

What happens to temperature during a phase change?

During a phase change, temperature remains constant until the phase change is complete, even though energy is added or removed because it changes its potential energy, not kinetic.

What happens to particles during a phase change?

Particles either break intermolecular forces or form new intermolecular forces.

What happens during an endothermic phase change?

Energy is absorbed and used to overcome intermolecular forces between particles

What happens during an exothermic phase change

Energy is released as new intermolecular forces form between particles

Which phase changes are endothermic?

Melting, vaporization, sublimation

Which phase changes are exothermic

Freezing, condensation and deposition

What do flat sections of a heating curve represent?

Phase changes where energy changes intermolecular forces rather than increasing temperature