S4 - Chemistry Test (1) Flashcards
What happens in a chemical reaction?
A new substance/substances are formed and the reactants turn to products
What is the rate of reaction?
The measure of how fast or slow a chemical reaction takes place/products are produced
What is a catalyst?
A substance which speeds up the rate of reaction but is chemically unchanged at the end of the reaction
What are the four factors which affect the rate of reaction?
- Concentration
- Particle size
- Temperature
- Use of a catalyst
What is the equation to find the average rate of reaction?
Av. rate = Change in product / Change in time
Name the seven diatomic elements
- Hydrogen
- Nitrogen
- Oxygen
- Fluorine
- Iodine
- Chlorine
- Bromine
What does the nucleus of an atom contain?
Protons and Neutrons
Where are the electrons in an atom?
In the shell/orbiting the nucleus
What is the mass of each particle that makes up an atom?
Proton = 1
Neutron = 1
Electron = 0
What is the charge of each particle in an atom?
Proton = positive
Neutron = none
Electron = negative
How do we tell what the atomic no. of an atom is?
The no. of protons it contains
How do we tell what the mass no. of an atom is?
The no. of protons + neutrons
Why are atoms neutral?
They contain the same no. of protons and electrons (+ & -)
How can we find the no. of neutrons in an atom
Mass no. - atomic no.
What is an isotope?
Atoms with the same atomic no. but different mass no.
What do elements in the same group have in common?
They have similar chemical properties
In nuclide notation, what do the no. on top and below the element represent?
On top: Mass no.
Below: Atomic no.
What are the 3 types of radiation?
- Alpha
- Beta
- Gamma
Why are atoms radioactive?
Their nuclei are unstable
What are the masses and the charges of the different types of radiation?
Alpha: 4, +2
Beta: 0, -1
Gamma: 0, 0
What is the penetrating power and the objects that stop the different types of radiations?
Alpha: Short, Paper
Beta: Medium, Aluminium
Gamma: Long, Lead or concrete