L1: Energy, Matter, and Atomic Models

Chemistry

The study of the properties of matter and how matter changes

Chemistry

It is known as "Central Science"

Chemistry

the science that describes matter

Organic chemistry

the study of compounds containing hydrogen

Organic chemistry

Deals with hydrocarbons and its derivatives.

Biochemistry

Chemistry of living things

Physical Chemistry

Behavior of matter

Oxygen

most abundant element in earth's crust, ocean, and human body

Matter

Anything that has mass and takes up space

Mass

Measure of the quantity of matter.

Kinetic energy

Energy in motion.

Endothermic

Absorbs heat

melting

solid to liquid

condensation

Gas to liquid

sublimation

solid to gas

Chemical properties

Exhibited by matter as it undergoes changes in composition

Extensive Properties

If this doubles the property, what is it?

Intensive Properties

If the property is unchanged by altering the sample size, what is it?

Chemical Change

when a 2 solution are mixed forming a solid

Physical change

a chemical change has taken place

Mixture

Has variable Composition (e.g. 70%, 80% or 95% ethanol in water)

Mixture

may be separated through physical means

Pure Substance

Fixed composition (can't be separated)

Dalton's Theory

A theory says that all matter is composed of atoms and these cannot be made or destroyed.

Mass Number

The sum of the number of protons and the number of neutrons in an atom's nucleus.

Nuclide Symbol

Represents the composition of the nucleus

The Atomic Weight

Many elements occur in nature as mixtures of isotopes.

Leucippus and Democritus

said that atom is a solid indivisible sphere

Leucippus and Democritus

Greek word "Atomos" - uncuttable

Aristotle and Others

said that Matter is made up of four elements

John Dalton

atom as solid sphere indivisible

electrical forces

elements of chemical compound are held together by _____

Humphry Davy

Relationship between the amount of electricity used in electrolysis and the amount of chemical reaction that occurs.

Michael Faraday

that electrons are electric ions

Cathode-Ray Tube Experiment

Most convincing evidence of electrons

Cathode-Ray Tube Experiment

Uses Plum pudding model

Cathode-Ray Tube Experiment

A discovery of electron that was made by Joseph John Thomson in 1897

Oil-drop Experiment

A discovery of electron that was made by Robert Millikan in 1909

Oil-drop Experiment

Determine the charge of electrons

Canal Rays Experiment

discovery of protons by Eugen Goldstein

Canal Rays Experiment

Cathode-ray tube also generates a stream of positively charged particles

Canal Rays Experiment

These positive rays, or positive ions, are created when the gaseous atoms in the tube lose electrons.

(Ernest) Rutherford's Model

The Scattering Experiment is made by whom in 1910?

Rutherford's Model

Atoms consist of very small, very dense positively charged nuclei

Nuclear Model

Positive charge localized in the NUCLEUS

H.G.J. Moseley

the one who arranged elements by atomic number

J. Chadwick

the one who discovered the neutron

Bohr's Planetary Model

Electrons orbit the nucleus in energy levels

Louis de Brogli

proposed the idea of wave-like nature of electrons

Quantum mechanics

Based on the wave properties of matter

Werner Heisenberg's Uncertainty Principle

it is not possible to know both the momentum and the position of a particle at the same time

Erwin Schrödinger's Wave Equation

It estimates the position of electrons and quantifies energy levels.

Atomic Orbitals

Regions of space in which the probability of finding an electron is high.

Erwin Schrödinger

Made electron cloud model & quantum mechanical model

Oxygen

common element in periodic table

nitrogen

most abundant element in air (atmosphere)

hydrogen

most abundant element in universe

Inorganic chemistry

Focuses on inorganic compounds, metals, and minerals.

Analytical chemistry

the identification of the components (qualitative analysis)

Analytical chemistry

amount of each substance (quantitative analysis)

Biochemistry

Study of processes in living organisms.

Volume

The amount of space an object takes up

Energy

The capacity to do work or to transfer heat.

Potential energy

Energy at rest.

Exothermic

Releases heat

Solids

Molecules packed close together orderly

Solids

Definite shape and volume

Liquids

assumes any shapes like the shape of container

Liquids

Molecules are close but randomly arranged

Gases

A state of matter, have no fixed shape and fills in any container

Gases

expands definitely, and highly compresible

Gases

Molecules are far apart

freezing

liquid to solid

boiling/ evaporation

Liquid to gas

deposition

gas to solid

Physical properties

Can be observed or measured without changing the identity of the substance.

Physical properties

color, hardness, melting point, and boiling point is an example of what?

Chemical properties

hydrogen has the potential to ignite and explode given the right conditions is an example of what?

Extensive Properties

dependent on the amount of substance present

Intensive Properties

independent of the amount of substance present

Chemical change

Occurs when one or more substances are used up, and new substances are formed.

Chemical change

the change is "irreversible"

Physical change

No change in chemical composition, and the change is reversible.

Homogeneous Mixtures

a mixture in which the composition is uniform (solutions)

Heterogeneous Mixtures

a mixture in which the composition is distinguishable (suspension)

Compounds

Consist of atoms of two or more different elements bound together.

Elements

Consist of only one kind of atom

Atom

The smallest unit that retains the properties of an element.

John dalton

Uses experimental observation approach

Atomic Number

The number of protons in the nucleus of an atom, determining its identity.

Isotopes

Atoms of the same element with different masses.

Isotopes

Atoms with the same number of protons but different numbers of neutrons

democritus

uses philosophical approach

Saturn-like model

A discovery of electron that was made by Hantaro Nagaoka (1903)

H.G.J. Moseley

who studied X-rays given off by various elements?

Niels Bohr's Model

Describes electrons revolving around the nucleus in discrete circular orbits.

Bohr's Planetary Model

Each orbit thus corresponds to a definite energy level for the electron.