Unit 1 Flashcards
What does the term ‘redox’ stand for in chemistry?
Reduction-Oxidation reaction
True or False: In a redox reaction, electrons are transferred from one substance to another.
True
What is the substance that loses electrons in a redox reaction called?
Reducing Agent
What is the substance that gains electrons in a redox reaction called?
Oxidising agent
In a redox reaction, what is the process of losing electrons called?
Oxidation
In a redox reaction, what is the process of gaining electrons called?
Reduction
Define Temperature
A measure of the average kinetic energy of the particles in a substance
Define the Activation Energy
the minimum kinetic energy required by colliding particles before a reaction may occur.
What is the weakest intermolecular force called?
London Dispersion Forces
Difference between Intermolecular and Intramolecuoar
Intermolecular- bonds from molecule to molecule
Intramolecular- bonds between the atoms, making up the molecule
Define Electronegavity
a measure of the attraction which an atom has for the electrons in the bond
What Atoms can have hydrogen bonds?
Nitrogen, Oxygen, Flourine
Why does electronegativity decrease down a group?
Increased shielding effect from more energy levels - increased distance between the last energy level and the nucleus
Metallic Bonding Structure
Positive Ions and a delocalised ‘sea’ of electrons
3 elements that form Covalent Networks
Carbon
Boron
Silicon
Why do monoatomic elements have low mp and bp
They have low melting and boiling points as they are easily separated by overcoming the weak forces of attraction between the atoms
They also have weaker LDF due to having a low number of electrons
Why does the covalent radius decrease along a period?
The greater attraction between the increased number of protons (increased nuclear charge) and electrons, pulls the electrons closer
Why does the covalent radius increase down a group?
This is because of the screening effect of the filled inner electron levels. These electrons screen or shield the outer electrons from the nuclear charge.
Define the first ionisation energy
The first ionisation energy is the energy involved in removing one mole of electrons from one mole of atoms in the gaseous state.
NH4 has polar bonds between the atoms, but the molecule is…
Non-Polar overall because the delta+ and delta- poles are in the same place due to the tetrahedral structure
When a bond has no Ionic character at all
It is a pure Covalent bond with the two atoms having the exact same electronegativity
How is a polar covalent bond formed?
when a shared pair of electrons are not shared equally. This is due to one of the elements having a higher electronegativity than the other
