Topic C1-Atomic Structure And The Periodic Table Flashcards
What are Atoms?
They contain protons, Neutrons and Electrons.
-Have a radius of 0.1 nanometres.
What is the Nucleus?
Contains Protons and neutrons and has a positive charge.
What are the relative masses and charges of the particles?
Proton:1-:1
Neutron:1:0
Electron:0:-1
What are Electrons?
Negatively charged and move around the nucleus in the shell. Number of protons is the same as the number of electrons.
The Nuclear symbol?
-The top number is the mass number, which tells you how many protons and neutrons there are.
-The bottom number is the atomic number, tells you the number of protons.
-To get the number of neutrons you subtract the atomic number from the mass number.
What is an element?
A substance made up of atoms that all have the same number of protons.
What is an isotope?
-Different forms of the same element, have the same number of protons but a different number of neutrons. Have the same atomic number but different mass numbers.
What is the formula for Relative Atomic Mass?
Isotope abundance X isotope mass number
——–
Sum of abundances of all isotopes
What is a compound?
Substances formed from two or more different elements that have been chemically joined.
What is a mixture?
-A compound made up of two or more elements which are not chemically joined.
What did John Dalton discover?
-Start of 19th century, atoms were described as solid spheres.
What did JJ Thomson discover?
-1897-Plum pudding model meant atoms aren’t solid spheres, it is a ball of positive charge with electrons in it.
What did Ernest Rutherford discover?
-1909-Alpha particle Scattering experiment-Shot a beam of positively charged particles at a thon sheet of gold foil, some were deflected which led him to conclude most of an atoms mass is concentrated at the centre called the nucleus.
What did Niels Bohr discover?
-1911-Electrons are in shells orbiting the nucleus.
What did James Chadwick discover?
-1940-Discovered there are neutrons in the nucleus.
What is the Electronic structure of an Electron shell?
1st shell-2 electrons
2nd shell-8 electrons
3rd shell-8 electrons
