DP Chem Flashcards

Elements

Simplest Compounds: Cannot be broken down or decomposed into more stable substances by chemical reaction

Contain one type of atom (all with the same amount of protons)

Can either be classified as metals (like silver), non-metals (nitrogen), or metalloids (silicon)

Isotopes

When elements have the same amount of protons but different amounts of neutrons. This leads to the same chemical properties but slightly different physical properties. Ex. For Neon, lighter isotopes diffuse more easily and have a lower melting point than heavier isotopes

Compounds

Pure substances made up of atoms from 2+ elements.

The physical and chemical properties differ from elements it makes up.

Solvation

When compounds dissolve, the individual ions and atoms interact with the solvent molecules which creates a process called Solvation

Hydration

Solvation with water at the solvent

Solute

Thing being dissolved (solid)

Solvent

Liquid in a solvation reaction

Miscible

Liquids that mix together

Form a homogenous mixture when mixed

Immiscible

Liquids that don’t mix together and form different layers (water and oil)

Mixtures

Consists of more than one compound or element but not chemically bonded

Can be seperated by a physical method

Melts and boils over a range of temperatures

Shows all the chemical properties of elements and compounds in it

Heterogenous or Homogenous (focuses on the uniformity of the substance)

Seperation Techniques

Ways to seperate components from complex mixtures

Filtration

Used to separate substances in a mixture by solubility

Distillation

Both simple and are fractional are used to seperate miscible liquids by boiling points in mixtures

Crystallisation and Evaporation

Used to seperate solutions by volatility (easy evaporation under certain temperatures) in mixtures

Separating Funnel

Separates immiscible liquids by insolubility (polarity) in a mixture

Kinetic Molecular Theory

All substances made up of moving particles and physical properties determined by arrangement of particles

Solid

A state of matter in which there’s a fixed volume, fixed shape, higher density than liquids, not able to flow and has limited compressibility. Made up of a lattice structure, and particles will repel if brought closer. Balanced forces keep each particle in fixed positions and the only time they seperate is when the solid is heated giving the particles kinetic energy and causing the structure to expand as the distance increases.

Liquid

State of matter which doesn’t have a fixed shape and flows easily but has fixed volumes and are limited in compressibility with a density usually higher than gases but less than solids. The particles are slightly further apart than in a lattice structure and have little space apart when compressed. Attractive forces make the particles able to move around freely through the structure but not leave it unless past it’s boiling point (hence the definite volume). When heated, the particles vibrate more and the structure expands.

Gas

State of matter thats easily compressible with low density, it diffuses easily with no fixed shape or volume. The particles are far apart, which allows for such easy compression. Intermolecular foces are negligeable due to the normally large distance particles normally have outside of collissions.

Lattice Structure

Structure consisting of organised and repeated set of atoms in a 3-dimensional space

Intermolecular Forces

Attractive and repulsive forces between particles

Sublimination

The change in state from a solid directly into a gas without becoming a liquid

Temperature

Measured by a thermometer which reflects the random motion of particles. Temperatures above absolute zero have kinetic energy

Absolute Zero

When temperature is 0 kelvin (K)

kelvin (K)

Unit of Absolute of Thermodynamic Temperature

Kelvin to Celsius

Kelvin is 273.15 higher than Degrees Celsius

Atoms

The smallest particles that can take place in a chemical reaction and fundamental units of matter. Composed of protons, neutrons and electrons.

Ions

Formed when electrons are added or removed from an element

Radioisotopes

Unstable isotopes, nuclei break down spontaneously in a process called radioactive decay and these isotopes are called radioactive

Relative Atomic Mass

Weighted average mass of the atoms of its isotopes compared to one-twelfth of the mass of carbon-12

Light

Electromagnetic wave described by wavelength

Electron Excitation

Gaseous atoms beign excited emit lights of certain frequencies. These can be thermal or electrical. This happens when a substance is vaporised and a flame is formed or when a high voltage is passed across a tube of gaseous sample of the element at low pressure.

Orbital

Volume of space around the nucleaus of an atom in which there is high likelihood of locating an electron

Spin

Electrons spin and generate a magnetic field, either clockwise and anti-clockwise depicted by an arrow pointing up or down. A singal atomical orbit has two electrons called a spin bar that if correct rotate in opposite directions.

Orbital s

S Sublevel holds 2 electrons. Spherical and exist individually.

Orbital p

Sublevel holds 6 electrons. Dumbbell shaped and exists in groups of three with right angles.

Orbital d

Sublevel holds 10 electrons and exist in groups of 5.

Orbital f

Sublevel holds 14 electrons

Covalent Bonds

Formed when orbits overlap and merge to form molecular orbitals

Condensed Electron Configurations

Written by replacing the inner electron configuration with noble gas symbol

Transition Elements

Elements from scandium to zinc from first row of d-block. Contains 10 metallic elements.

Ionization Energies

Measure of amount of energy needed to remove one mole of electrons from gaseous atoms. The greater the electrostatic attraction, the harder it is to pull the electrons from the atom.

Atomic Radius

As the distance of the outer electrons from the nucleus increases, the attraction of the positive nucleus for the negatively charged electrons falls. This causes the ionization energy to decrease.

Nuclear Charge

When the nuclear becomes more poditive due to additional protons, its attraction on all the electrons increases. This causes the ionization energy to increases.

Shielding Effect

Valence electrons are repelled by all the other electrons in the atom in addition to being attracted by the positively charges nucleus. Theoouter valence electrons are shielded from the attraction of the nucleus. Generally the greatest with electrons closest to the nucleus where there is the highest nucleus density.