Exam 1 terms Flashcards
What are variables?
Variables are things or factors that can influence the outcome of an investigation
What is a scientific model?
A model is a representation of an idea, and object or even a process or a system that is used to describe and explain something that cannot be experienced directly
What is an ion?
When an atom loses or gains electrons. This will result in the atom having a positive or negative charge.
What is an isotope?
Isotopes are atoms with the same number of protons but different number of neutrons. Therefore different mass.
What is an element?
An element is a pure substance made up of one type of atom and cannot be broken down into simpler substances.
What is a diatomic element?
Elements which naturally occur as molecules made up of two identical atoms chemically bonded together. Must be identical.
What is diffusion?
The movement of particles from an area of high concentration to one of low concentration, until the particles are evenly distributed.
What is a compound?
A chemical compound is a substance that consists of two or more different elements chemically bonded together in a fixed proportion
What does IUPAC mean?
International Union of Pure and Applied Chemistry
What is a binary compound?
A binary compound is one in which there are atoms from two different elements present
What is valency?
Valency is the number of bonds an atom of a particular element can make when bonding with another atom
What is the order of valency?
0,1,2, skip ten groups, 3,4,3,2,1,0
What is a scientist
A person who wants to know more about the world.
What do scientists use?
investigations, tests and experiments in order to answer questions, solve problems or explain different phenomena.
What are the three types of variables?
Independent, dependent and fixed variables
What is an atom?
All matter is made of tiny particles called atoms. Smallest part of an element that can exist on its own.
What is a nucleon?
proton and neutrons together.
What is the symbol for a proton, the charge and location?
P+, positive, nucleus
What is the symbol for a neutron, the charge and location?
N°, neutral, nucleus
What is the symbol for a electron, the charge and location?
e-, negative, orbiting around the nucleus
What does the nucleus make up in the atom?
The volume
Why are atoms always beau real?
Protons are equal to electrons therefore atoms are always neutral
How many elements, groups and periods are on the periodic table?
118 elements, 18 groups and 7 periods
What is the symbol for the atomic number? What does the number tell us?
The symbol is a z. Tells us the number of protons and electrons present in the nucleus of the atom.
What is the symbol for the atomic mass? What does it tell us?
The symbol is A. It tells us the number it nucleons in he nucleus.
What is the formula to find out the neutrons?
number of neutrons=
= A - Z
= number - number
= number of neutrons
How many electrons can the Bohr model hold in the first energy level? second energy level?
2
8
8
8
What is the oder we follow when placing electrons?
Top, bottom, side, side, repeat
What is group 1 called?
alkali metals
what is the name of Group 2
Alkali earth metals
What is the name of group 17?
halogens
what is the name of group 18?
noble gases or inert gases
another name for semi-metals?
metalloids
what is electrical conductivity?
the ability for a substance to allow a charge to flow through it
what is heat conductivity?
the ability of a substance to transfer heat.
Metallic lustre or dullness
describes how shiny or dull a substance is
Malleable
the ability of a substance to be hammered and shaped without breaking
ductile
the ability of a substance to be drawn into think threads
string or brittle
how easily a substance breaks
Name the five characteristics of metals.
- Strong, malleable, and ductile
- High melting and boiling points
- Good conductors of electricity and heat
- Mainly solids at room temperature ( mercury is an exception, and is a liquid at room temperature)
- Becomes shiny when polished, therefore lustre
Give the five characteristics of non-metals.
- Brittle (except diamond)
- Low melting and boiling points (except diamond)
- poor conductors of electricity and heat
- solids, liquids and gases at room temperature
- full looking (except diamond)
Give the 7 diatomic elements
Have no fear of ice cold bear Hydrogen Nitrogen Fluorine Oxygen Iodine Chlorine Bromine
What is an impure substance?
Result of a combination of two or more substance that have not reacted chemically. Mixtures may be separated by physical processes like filtration, evaporation and distillation.
What two groups can mixtures be divided into?
Heterogeneous and homogenous
What is heterogenous mixtures?
Components parts can be distinguished.
Eg. ice in soda, cereal in milk, oil mixed with water
What is homogenous mixtures?
Component parts cannot be distinguished.
Eg. Tap water, atmospheric air, steel, salt water
What is the solute, solvent and solution?
Solute is what is being dissolved.
Solvent is what is doing the dissolving.
Solution is the final product when it is all mixed together.
What is a chemical formula?
a symbolic representation of a compound and gives the following information about a compound:
• the name
• the elements present
• the ratio of the elements combined
What is a metal + non metal called?
Ionic
What is non metal + non metal called?
Molecule
How do we determine the chemical formula for a binary compound?
We use the system called swop and drop
How do we determine the chemical name for a binary compound?
It firstly depends whether it’s is ionic compound or molecule
Rules for naming ionic compound
• Name of the first metal written first and the same
• Name of the second element changes to end with ide
Eg. Sodium chloride
Rules for naming a molecule
- The second element ends with ide
- Add prefixes to the name of the elements to specify the number of atoms of a particular element are present
- mono is left out of the beginning of the first word.
- but other prefixes have go on the first word
Name the six prefixes
1 - mono 2 - di 3 - tri 4 - tetra 5 - penta 6 - hexa
What is a particle diagram?
A way of representing molecules and compounds. If they shapes are joined (touching) each other it means they have chemically bonded
Gives the tips of the particle diagram
- Hydrogen is always drawn smaller
* if multiples atoms, write the name of the central atom first
