atomic structure definitions Flashcards
What is an atom’s electrical charge
Neutral
Why is an atom electrically neutral
The number of electrons and neutrons are the same
What does the central nucleus contain
It contains the positively charged protons and the neutrally charged neutrons
What do the shells orbiting the nucleus contain
The negatively charged electrons
What is an atom
An atom is composed of a small,dense, positively charged nucleus at the centre which is composed of protons and neutrons this makes up most of the mass. It then also contains negatively charged electrons in shells orbiting the nucleus
What is the size of an atom
Atoms has a radius of 0.1nm or (1x10-10m)
The nucleus is less than 1/10000 of that of the atom
What is the atomic number
This is number of protons (in the nucleus of) an atom.
What is the mass number
This is the total number of protons and neutrons in (the nucleus of) an atom.
What is an element
An element is a substance that consists of only one type of atom and cannot be broken down into anything simper by chemical means.
How do elements differ?
The number of protons, neutron and electrons are different.(each element has a unique atomic number)
What is an isotope?
Isotopes are atoms which have the same number of protons (so they are atoms of the same element) but they have a different number of neutrons ( so they have a different mass number)
