Chemistry Clinical Sciences 1-3 Flashcards
Chemistry Revision from Lectures 1-3
What is matter?
Matter is anything that has mass.
What is a physical change?
Physical changes are the same material it just changes state.
In a physical change, if the material does not change, what does?
Energy needed to break/ make bonds.
What are properties of matter?
Density- Mass to volume ratio.
Melting point- Temperature solid to liquid.
Boiling point- Temperature liquid to gas.
Refractive Index- How light passing through a material is bent.
Malubility- The ability an object has to be shaped by hammering.
Ductility- The ability an object has to be shaped by pulling into a wire.
Electrical Conductivity- Ability to transmit electricity.
Heat conductivity- Ability to transfer heat.
What are intensive properties?
Give 3 examples of intensive properties.
Intensive Properties DO NOT depend on the amount of matter present. They are used to identify substances.
Density, colour and boiling point.
What are extensive properties?
Give 3 examples of extensive properties.
Extensive properties depend on the amount of matter present.
Mass, volume and weight.
What are physical properties a result of?
To examine the physical properties of a substance what must the substance be?
Molecular formula and intermolecular forces.
The substance must be PURE.
What are chemical properties a result of?
Electrons in the outer shell around the nucleus.
What are Colloids?
Mixtures which look homogeneous but are actually heterogeneous.
What is a phase?
A distinctive form of matter. Eg. gas, liquid or solid.
What is fixed about a pure substance?
How are pure substances separated or change identity?
Fixed set of physical properties.
Cannot be separated by physical processes and can only change identity by CHEMICAL METHODS.
How do you know when a substance is pure?
Examples of pure substances.
All molecules have the SAME MOLECULAR FORMULA in the substance.
Elements and Compounds
What is a mixture?
TWO or MORE SUBSTANCES which are NOT CHEMICALLY BONDED together.
How are Mixtures separated?
Physical Processes.
What is a homogenous mixture?
SINGLE PHASE mixture with the SAME PROPERTIES throughout the mixture with UNIFROM CHARACTERISTICS.
What is a heterogenous mixture?
Has MUTIPLE PHASES with VARIABLE PROPERTIES with a NON- UNIFORM APPEARANCE.
What is an element?
Is the simplest form of matter that has a unique set of properties. It cannot be split into two or more simple substances by chemical means.
What is a compound?
Is a substance that contains two or more elements chemically combined into a fixed proportion.
What is a molecule?
2 or more atoms bonded together. Atoms in defined proportions.
What did Dalton describe in his Atomic Theroy?
All Matter is composed of atoms.
Different elements have different atoms which are characterised by atomic weight. All atoms of same element are identical.
Compounds are two or more atoms in fixed ratios. For example water formula is H2O and Dalton thought the formula for water was OH.
Chemical reactions rearrange atoms which changes the ratios so changes the compound.
Properties of Atoms
- NUCLEUS contains almost all of the atom’s MASS.
2. Combining power is the atom’s ability to form chemical bonds (VALENCY).
What is Valency and what does this depend on?
VALENCY is the NUMBER OF BONDS an element can make, which all depends on how many ELECTRONS are in the element’s HIGHEST ENERGY LEVEL.
What are electrons?
What is the nucleus?
ELECTRONS are negatively charged and determine atoms physical and chemical properties.
Nucleus is positively charged and contains the atoms neutrons and PROTONS- which is also known as the MASS NUMBER.
What is the Relative Atom Mass Definition?
Mass of one atom of an element divided by the mass of 1/12 of an atom of carbon- 12.
(Average mass of each of an element’s isotopes).
What is relative molecular mass?
RMM/Mr is the mass of 1 molecule.
What is a solution?
HOMOGENOUS MIXTURE formed when one substance DISSOLVES in another.
What is a Solute?
What is Solvent?
The substance that dissolves.
The substance that does the dissolving.
How do you separate a mixture?
In a mixture use the differences in physical properties.
Name and describe the physical processes which separate mixtures.
FILTRATION- Particle size (Liquid/ Solid).
CRYSTALISATION- Solubility (Solid in Solution).
EXTRACTION- Solubility (Solid/ Liquid in Solution).
DISTILLATION- Components selected by boiling point (Liquid to liquid).
MAGNETISATION- Magnetic metals from other compounds.
CHROMATOGRAPHY- Components selected by affinity (attraction) to stationary phase.
What is an atom made up of?
Protons, neutrons and electrons.
What are nucleons?
Protons and Neutrons.
What is the mass number/ atomic mass?
Protons and Neutrons
What is the atomic number?
Number of protons.
What is an orbital?
Regions of space with electrons occupy.
What is a shell?
Orbitals are grouped into families which are called shells.
Give an example of an orbital, a sub shell and a shell.
Orbital- 2px
Sub shell- 2p
Shell- 2s+ 2p
What is an isotope?
An ISOTOPE has a different number of neutrons in each atom of the same element so different isotopes are different forms of the same element.
What is the relative atomic mass of an element?
The mass of each isotope added together divided by how many isotopes there are for that element= Average mass.