Periodicity Flashcards
(27 cards)
Why does atomic radius decrease across a period?
- Increase in nuclear charge
- Same shielding
Why do metals have a higher melting point as you go across a period?
Metallic bonds get stronger due to increasing positive charge
How does having more atoms impact strength of VdW’s?
Increases VdW
Why do monoatomic atoms have low melting points?
Due to weak VdW
What 2 properties increase as you go down Group 2?
Atomic radius
Reactivity
Explain why first ionisation energy decreases down Group 2
Extra electron shells increase distance from nucleus and shielding
Why does reactivity increase as you go down Group 2?
More shells increases distance from nucleus and shielding so it is much easier to lose electrons
Why does melting point decrease as you go down Group 2?
- Ionic radius increases
- Effect of nuclear charge decreases
- Less energy required
Describe a typical metallic lattice structure
- Bed of positive ions
- Surrounded by sea of delocalised electrons
What kind of ions do Group 2 elements form?
+2
What two properties decrease as you go down Group 2?
First ionisation energy and boiling points
Does solubility of metal hydroxides increase or decrease as you go down Group 2?
Increases
What is the trend in solubility of metal sulfates as you go down Group 2?
They decrease
What are some uses of Group 2 elements?
Ca(OH)2 used to neutralise acidic soils
What Group 2 element can be used to treat indigestion?
Mg(OH)2 - Antacid/’Milk of Magnesia’
How is barium used in medicine?
Barium meals for x-rays
Which Group 2 element can be used in titanium extraction?
Magnesium
What state are the following at room temperature:
- Fluorine
- Chlorine
- Bromine
- Iodine
- Fluorine: Pale yellow gas
- Chlorine: Green gas
- Bromine: Red-brown liquid
- Iodine: Grey solid
Explain why boiling points increase as you go down Group 7
- Strength of VdW’s increases
- Atomic radius increases
Why does electronegativity decrease as you go down Group 7?
Electrons are further from the nucleus and shielded by more electrons
Why can halogens displace each other?
Reactivity decreases as you go down
Why does reactivity of halogens decrease as you go down Group 7?
- Outer shell is further from the nucleus
- Electrons are less strongly attracted to nucleus
Does oxidising strength of Group 7 elements increase or decrease as you go down?
Decrease
