Atomic structure and properties of fundamental particles Flashcards
What is an atom?
The smallest particle of a chemical element that can exist and participate in chemical reactions
What does an atom contain?
Three subatomic particles; electrons, protons and neutrons
Describe the properties of the three subatomic particles found in atoms.
Protons have a charge of +1 and a relative mass of 1
Neutrons have a neutral charge and a relative mass of 1
Electrons have a charge of -1 and a negligible mass of 0.0005
Where is the mass of an atom concentrated and why?
In the nucleus because this is where the protons and neutrons are and they are the two sub atomic particles with the heaviest mass.
What keeps the nucleus of an atom together?
Nuclear forces
How are electrons arranged in an atom and why?
Electrons are arranged in energy shells around the nucleus, which they are attracted to because of the positive charge of the nucleus
What gives an element its chemical properties and why?
How many electrons there are in the outer shell
What is an atoms overall charge and why?
It is neutral because any atom has an equal amount of protons and electrons
What is another term for ‘atomic number’ and what does it mean?
Proton number; it means the number of protons in the nucleus
Why is an elements atomic number significant?
An elements atomic number is significant because each element has its own unique proton number and this is used to organise the periodic table
What is the ‘nucleon number’?
The nucleon number is the mass number, which is the number of subatomic particles in the nucleus (number of protons and neutrons)
How could you work out the number of neutrons in an atom?
Mass number - Proton number
What is an isotope of an element?
An atom of an element which has a different amount of neutrons and hence a different mass
Why are protons and neutrons sometimes called nucleons?
Because they are found in the centre of the atom
What forces hold together the electrons and protons?
Electrostatic forces
