Topic 4 - Atomic Structure - 4.1 - Atoms and Isotopes Flashcards
Give an approximation for the radius of
an atom.
1x10⁻¹⁰ metres
What are the three subatomic
constituents of an atom?
- Proton
- Neutron
- Electron
Where is most of the mass of an atom
concentrated?
In the nucleus.
Approximately what proportion of the total radius of an atom is the radius of the nucleus?
1/10,000
Describe the arrangement of protons,
neutrons and electrons in an atom.
●The protons and neutrons are found in the atom’s nucleus
●The electrons are found in discrete energy levels around the nucleus
What type of charge does the nucleus of
an atom have? Why?
●Positive charge
●The nucleus contains protons and neutrons
●Protons have a positive charge
●Neutrons have no charge
Give two ways that an atom’s electron
arrangement can be changed.
- Absorbing electromagnetic radiation
- Emitting electromagnetic radiation
Explain how an atom’s electron arrangement changes when it absorbs EM radiation.
●Electrons move further away from the nucleus
●They move to a higher energy level
Explain how an atom’s electron arrangement changes when it emits EM radiation.
●Electrons move closer to the nucleus
●They move to a lower energy level
How does the ratio of electrons to protons in an atom result in the atom having no overall charge?
●The number of protons is equal to the number of electrons
●Protons and electrons have equal and opposite charges, so charge cancels
What do all forms of the same element
have in common?
They all have the same number of
protons.
What is the name given to the number of
protons in an atom?
Atomic Number
What is an atom’s mass number?
The total number of protons and
neutrons in the atom.
What is an isotope of an atom?
An atom of an element that has a different number of neutrons, but the same number of protons.
How do atoms turn into positive ions?
●They lose one or more of their outer electrons
●Electrons are negatively charged, so the resultant charge of the atom is positive
