UNIT 1 Flashcards
What are isotopes?
Isotopes are atoms of the same element that have the same atomic number but a different mass number
What is Relative Atomic Mass (RAM)?
It is the average mass of the atoms in an element taking into account the different isotopes and their relative abundance
What are elements in the periodic table arranged in?
They are arranged in atomic number
How are ions formed?
They are formed when atoms gain or lose electrons
What happens if an atom gains an electron?
It becomes a negatively charged ion
What happens if an atom loses an electron?
It becomes a positively charged ion
What do atoms achieve by forming ions?
They achieve the same electron arrangement as the nearest Noble Gas
What are Diatomic molecules made up of?
They are made up of only two atoms
What are the 7 diatomic elements?
Oxygen, Fluorine, Chlorine, Nitrogen, Hydrogen, Iodine, Bromine
How are atoms joined together?
They are joined together by bonds
What are atoms?
They are the building blocks which make up everything in the universe
Why do atoms bond?
Atoms bond to achieve the most stable outer electron arrangement-a full outer shell
What is a covalent bond?
A covalent bond is 2 positive nuclei held together by their common attraction for the shared pair of negative electroms
What are covalent bonds formed between?
2 non-metals
What do you need to break a covalent bond?
Lots of energy as they are extremely strong forces of attraction.
How do atoms form bonds?
By using the electrons in their outer most energy level
What do bonding diagrams do?
They give a simplified picture of an atoms outer electrons
What is everything in the world made out of?
118 elements
What do molecules exist in?
3 dimensions
What does the shape of a covalent molecule depend on?
The number and orientation of central bonds around the atom
How can you show the shape of a molecule?
By using a perspective drawing
What are the 3 types of perspective bonds?
—straight
—> wedged
- - > dashed
What are the diagram names for elements with different numbers of substances?
If there is 1 substance present: linear
If there is 2 substance present: angular
If there is 3 substance present: trigonal pyramidal
If there is 4 substance present: tetrahedral
What is a proton?
A proton is a positively charged particle with a mass of 1 amu, and it is located in the cell nucleus
What is an electron?
An electron is a negatively charged particle with a mass of nearly 0 amu, and it is found orbiting the nucleus
What is a neutron?
It is a particle with a neutral charge which is found in the nucleus of a cell, it has a mass of 1 amu
What are atoms made up of?
Protons, neutrons, electrons
What is broken when covalent molecular compounds melt or boil?
The weak intermolecular forces are broken
What is left intact when covalent molecular compounds melt or boil?
The strong covalent bonds are left intact
If less energy is required in melting covalent molecular compounds…
Less energy required = low melting and boiling points
What do Covalent Networks exist as?
They exist as giant network structures held together by covalent bonds