Atoms Flashcards
What are atoms represented as?
Chemical symbols eg Mg magnesium
how do you tell the period from the atomic structure
How many electrons in the outer shell
How can you tell an elements period from the structure
How many shells there are
What is the relative atomic mass? Calculation
Mass x percentage
What is a relative atomic mass? Definition
The average value of the isotopes in an element
What is an element called if there are more neutrons than protons and electrons
Isotope
More protons =
Positive isotope
What is a noble gas
In group 8 and is unreactive because all its shells are full
Group 7 name
Halogens
Group 8 is called
The noble gasses
Group 1 is called
Alkaline metals
What is the middle section on the periodic table called
The transition metals
What is a protons relative charge
+1
What is a neutrons relative charge
0
What is an electrons relative charge
-1
Who discovered electrons
J.j Thomson
Who discovered protons
Ernest Rutherford
Who discovered neutrons
Chadwick
Before protons were discovered how was the PT arranged
In order of atomic weights
Describe the ‘plum pudding’
Atom is a ball of positive charges with negative electrons in it
What was Mendeleevs progress of the PT
He left gaps for elements he predicted would exist in the future and was eventually proved right
How many elements r in the PT
118
Before electrons were discovered what was an atom
Tiny spheres that couldn’t be divided
What side of the periodic table r metals on
Left
What side of the periodic table r non metals on
Right
Properties of metals
Shiny, malleable, ductile, dense, high melting + boiling point, conductors,
What is in the nucleus of an atom
Protons + neutrons
Sum of protons and neutrons = ??
The mass number
