Atoms and The Periodic Table Flashcards
What are atoms made out of?
Protons, electrons and neutrons.
Where is the mass of an atom situated?
In it’s nucleus, which contains protons and neutrons.
Which two particles have the same mass?
Neutrons and protons.
Are electrons positively or negatively charged?
Negatively charged.
What is the mass number?
The total number of protons and neutrons in the nucleus. It is the top number.
What is the atomic number?
The number of protons in the nucleus. Meaning it has the same number of electrons. It is the bottom number.
What are isotopes?
For any given element, the number of of protons is fixed, but isotopes are when the number of neutrons differ. This changes the mass.
What is likely to happen when isotopes have more neutrons than protons?
More likely to decay and can be unstable.
What is the relative atomic mass?
The relative atomic mass of an element is the average mass of its atoms, compared to 1/12th the mass of a carbon-12 atom. The relative atomic mass, A r, of an element is calculated from the mass numbers of its isotopes.
State the number of electrons allowed in shells 1-4.
Shell 1 has 2 electrons. Shell 2 and 3 both have 8. Shell 4 holds 2 on a standard periodic table.
Sodium has an atomic number of 11. Work out the electronic structure of the atom.
There is 11 protons total, so also 11 electrons. Shell 1 will have 2, shell 2 will have 8 (full), shell 3 will have 1. Written as 2,8,1.
What are the collumns in the periodic table classes as?
Groups
What are the rows in the periodic table classed as?
Periods.
What does the group number signify?
The group number indicates the number of electrons in the outer shell. Exception of group 0, who have full shells.
What does the period indicate?
The number of occupied electron shells in an atom.
What is group 1 of the periodic table?
The alkali metals.
What are the alkali metals?
Lithium, sodium, potassium, rubidium, caesium and francium.
What are the properties of alkali metals?
They react with oxygen to form oxides.
They react with water to form hydroxides and hydrogen gas.
They react with bromine and chlorine to form bromides and chlorides.
Does the reactivity increase or decrease down group 1?
Reactivity increases down the group. Can be dangerous to carry out without safety equipment.
What colour do the 3 alkali metals burn when subjected with oxygen?
Lithium burns crimson red.
Sodium burns orange-yellow.
Potassium burns lilac.
What are the group 7 elements known as?
The halogens.
What are the halogen elements?
Fluorine (toxic) chlorine (reactive) Bromine (both) Iodine (toxic in elemental form) astatine (highly radioactive, no one has even found it because it breaks down too quickly).
Does the reactivity increase or decrease when you go down the halogen elements?
Decreases as you go down.
What are the group 0 gases also known as?
The noble gases
