Atoms and Periodic Table most definitions Flashcards
Element definition
An element is a substance in which all the atoms have the same atomic number.
Atom
Smallest part of element that can exist.
Molecule definition
Two or more atoms bonded together.
Compound definition
Two or more different atoms chemically combined together.
Mixture definition
A mixture consists of two or more same elements not chemically combined together.
Nucleus definition
The centre of an atom and it controls the activities of the cell.
Proton definition
Proton is found in the nucleus. It has a charge of +1 and a relative mass of 1.
Neutron definition
Neutron is found in the nucleus of an atom and it has a charge of 0 and a mass of 1.
Electron
Electron is found in the shells of an atom and it has a charge of -1 and a negligible mass.
Electron shells
An electron shell is the outside part of an atom around the atomic nucleus.
Atomic number
Atomic number is the number of protons in an atom.
Mass number
The total number of protons and neutrons in an atom.
Isotope
An isotope is atoms of the same element, with the same number of protons but different numbers of neutrons.
What is the relative atomic mass?
The average value that includes the abundance of the isotopes of the element.
What is the plum pudding model?
The plum pudding model is a ball of positive charge with negative electrons embedded in it.
