The Guys who started it all
John Dalton suggested that atoms could not be divided into smaller particles. Is the true or false?
False – the atom can be divided into its subatomic particles
A carbon atom with 6 protons, 6 electrons and 6 neutrons would have a mass number of?
12
All atoms are made of these 3 subatomic particles
Protons, Neutrons and Electrons
An isotope is:
An element with the same number of protons but a different number of neutrons
Uranium-235 is used to produce electricity through the process of:
Nuclear fission. Neutrons are fired at uranium causing it to release energy which heats up water. The steam is used to generate electricity.
What did Rutherford believe was in the centre of an atom?
A nucleus
What is the difference between atomic number and mass number?
Atomic number is the number of protons, mass number is the number of protons + neutrons
What is the charge of protons, neutrons and electrons and where are they found?
Protons = positive
Neutrons = neutral
Electrons = negative
Protons and Neutrons are in the nucleus, electrons are in outer shells
The 3 types of radiation are:
Alpha, Beta and Gamma
What is the effect of radiation on biological cells?
Exposure to very high levels of radiation can damage body cells causing health effects such as skin burns and radiation sickness.
It can also mutate the DNA in the cells resulting in long-term health effects such as cancer.
The Bohr model of the atom shows that electrons exist in:
Orbitals/Shells
Elements in the periodic table are organised by:
Atomic number (number of protons) and number of valence electrons
Why do atoms have a neutral charge?
They have the same number of protons and electrons which cancels it out
Carbon-14 undergoes radioactive decay to become Nitrogen-14. What type of decay was this?
Beta
What are the effects of radiation pollution on the environment?
Radiation can get into the water and be harmful to plant and animal species. Animals that drink water or eat species contaminated with radiation can get radiation sickness or cell damage
Erwin Schrodinger developed the model of the atom we use today which is:
The electron cloud model
Elements in group 2 have a valency charge of:
+2
What is the valency of a sodium (Na) ion?
+1 (Na+)
The half-life of carbon 14 is:
5,730 years
How is Cobalt-60 used to treat cancer?
A ‘gamma knife’ focuses precise radiation on the cancer cells to stop them from dividing and kill them
The plums in Thomson's plum-pudding model of the atom represent:
Electrons
The periodic table was organised by:
Dimitri Mendeleev
How are cations and anions formed and what are their charges?
Cations are formed when an atom loses an electron and become positively charged. Anions are formed when an atom gains an electron and becomes negatively charged.
If the half-life of 100.0 grams of a radioactive isotope is 8 years, how many grams will remain in 32 years?
6.25 g
How is radiation used to measure the thickness of things like walls?
A Cs-137 detector is used. Radiation is released on one side and a detector senses the amount of radiation coming through and can calculate the thickness.