Chapter 2- Periodic table Flashcards
What are the group 1 metals called?
Alkali metals
What is a trend in reactivity?
It is the attraction between the outermost electron and the nucleus.
What is the nuclear charge of an atom?
It is the positive charge of an atom
The further away from the atom an electron is the easier it is to lose an electron and the harder it is to gain one
State why ,in terms of electrons, sodium and potassium are in group 1.
They both have 1 electron in their outer shell
Explain why there is a difference between sodium and potassium in their reactivity in water
Potassium is lower down in the group than sodium it is also more reactive.
Sodium reacts with bromine write the word equation
Sodium + bromine > sodium bromide
Calcium chloride contains ions, Ca 2+ , and chloride ions, Cl-. What is the formula for calcium chloride
CaCl2
Why is potassium more reactive than lithium?
The distance between the nucleus and the outer shell is further away meaning the force of attraction is weaker and the electrons are lost easier
What does the atomic number of an atom determine?
It’s position in the periodic table
Why are the noble gases so unreactive
Because they have a stable electron arrangement
Do metals tend to lose or gain electrons?
Lose
Do non metals tend to gain or lose electrons?
Gain
Do their melting points increase or decrease going up or down the group 0?
Their melting and boiling points increase as you go down the group
What do all alkali metals react with?
Water, they produce hydrogen and an alkaline solution containing the metal hydroxide
Does the reactivity of alkaline metals increase or decrease going up or down the group?
The reactivity goes up going down the group
What kind of ions do alkaline metals form?
They form +1 ions in reactions to make ionic compounds.
What kind of ions do the halogens form?
They all form ions with a single negative charge
How do halogens form covenant bonds
By sharing electrons with other non metals
What does displacement mean with halogens
When a more reactive halogen is combined with a less reactive halogen compound the more reactive halogen will displace the less reactive halogen taking its place in the compound.
Does the reactivity of halogens increase or decrease going up or down the group
It decrease going down the group
What does the attraction between the outermost electron and the nucleus depend on?
The distance between the two ( how many shells the atom has)
The size of the positive charge on the nucleus ( nuclear charge )
Which of the three key things that a trend in reactivity depends on gets outweighed by the other two?
The nuclear charge is outweighed by the size of the atom and the amount of shells shielding the attractive nuclear charge
State three trends as you go down group 1
They have lower melting and boiling points.
They have a higher relative atomic mass
They become more reactive
What kind of compound do alkali metals form with non metals? Explain?
Alkali metals don’t need much energy to lose their one outer electron so they generally lose it forming +1 ions. It is so easy for them to lose their outer electron that they only ever react to form ionic compounds
Describe the reaction of alkaline metals with water
They react vigorously
Lithium sodium and potassium float
They produce hydrogen. For potassium and below there is enough energy in the reaction to ignite hydrogen.
They form hydroxides that dissolve in water to give alkaline solution
Write the equation for sodium and water
Sodium + water > sodium hydroxide + hydrogen
Write the word equation for water and potassium
Potassium + water > potassium hydroxide + hydrogen
What are the trends as you go down the group 7
Become less reactive
Higher melting and boiling points
Higher relative atomic mass
Why do group 7 elements get less reactive as you go down the group from fluorine to iodine?
Because it’s harder for them to gain an extra electron because the outer shell is further from the nucleus
