Periodic Table Flashcards
What is a Atomic Number ?
An Atomic Number is the proton number .
What is the number of protons equivalent to ?
The number of protons is the number of electrons .
what is a mass number in a atom ?
A mass number is the nucleon number . It is made up of protons and neutrons .
what is the formula for a neutron number ?
The formula of a Neutron number is (mass number - proton number).
How many electrons can be placed in the 1st , 2nd and 3rd shells ?
in other words what is the electron configuration .
The 1st shell : Maximum of 2 electrons
The 2nd shell : Maximum of 8 electrons
The 3rd shell Maximum of 8 electrons
what are the elements in group 1 called
- the elements in the first group of the periodic table are alkali metals .
what happens when you go down the group in group 1 ?
Going down the group
- the atomic number increases
- the number of electrons increases
- Mass number increases
- melting & boiling point decreases .
- reactivity increases
elements of the same group (what the the changes and similarities)
- gradual change in physical properties (melting and boiling point , density , mass)
- similar chemical properties
The characteristics of the group 1 metals
- the group one metals are soft and can be easily cut
- the most reactive metal in the periodic table
- shiny when freshly cut
- low melting points
- low density
- conduct electricity
Why some lithium , sodium and potassium stored in paraffin oil ?
These metals are stored in paraffin oil because it is highly reactive with water and air , but if it is in the paraffin oil it prevents it from reacting with air and water .
what are the elements in group 7 called ?
The elements in group 7 are called “HALOGENS”
are the elements in group 7 metals ?
No. the elements in group 7 are non metals .
What happens the more you go down in group 7 ?
The more you go down
- the atomic number increases
- the number of electrons increases
- the mass number increases
- the melting and boiling point increases
- reactivity rate decreases .
what state are the elements in group 7 when it is in room temperature ?
- the first two ( fluorine and chlorine) are gases and room temperature .
- the third elements (bromine) it is a liquid at room temperature .
- The last two elements (iodine and astatine) are solids at room temperature .
what are the characteristics of the elements In group 7 ?
The elements in group 7 are the most reactive non-metals .