day 4 2-18 1.which metal would you expect to be more reactive - fr or cu? why? 2.which nonmetal...
DESCRIPTION
Periodic Trends Atomic radius: - Measure of size – radius of an atom - Atoms with more electrons do NOT necessarily have a larger atomic radiusTRANSCRIPT
Day 4 2-181. Which metal would you expect to
be more reactive - Fr OR Cu? WHY?
2. Which nonmetal would you expect to be more reactive - F OR Ne? WHY?
Periodic TrendsAtomic radius:- Measure of size – radius of an atom- Atoms with more electrons do NOT necessarily have a larger atomic radius
Periodic Trends- Atoms with more electrons do NOT necessarily have a larger atomic radius
1. Atoms get larger going down a group.
2. Atoms get smaller going across a period
So why?...
Periodic Trends- Atoms with more electrons do NOT necessarily have a larger atomic radius
As you move down a group you increase the number of energy levels in the atom and so the atom gets larger as expected.
Periodic Trends- Atoms with more electrons do NOT necessarily have a larger atomic radius
As you move across a period, # of protons increases and outermost energy level stays the same, the attractive force between elecs. and pros. pulls the atom tighter (closer to nucleus)
Review1. What element is in Group 2,
Period 3?
2. Name an element in Group 3
3. How many valence electrons in Xe?
4. Give me an element with 1 valence electron.
Alkali metals
7 valence
Nonmetals
Magnesium
Ductile
Halogens
1 valence
Noble gases
Atomic radius
Period 3
Day 5 2-191. Why does the size of an atom
decrease moving across a period?
2. What is more reactive Cl or Ar – Explain!!!
Review1. What element is in Group 2,
Period 3?
2. Name an element in Group 3
3. How many valence electrons in Xe?
4. Give me an element with 1 valence electron.
Partner Review1. What element is in Group 17,
Period 3?
2. What family of elements is the element above in?
3. How many valence electrons does it have?
Periodic TrendsWhat are ions?
- atoms that are charged due to the loss or gain of
electrons- If an atom loses elecs. it becomes smaller and positive
- If an atom gains elecs. it becomes larger and negative
Notes page 4
Periodic TrendsWhat are ions?- If an atom loses elecs. it becomes smaller
- If an atom gains elecs. it becomes larger
PAGE 176-179Which elements gain elecs.? Which elements lose elecs.? Pattern?
Periodic TrendsElements on the right side of the periodic table form _________ ions
Elements in the same group form ___________ ions
negative
The same
Day 2 3-21. Which halogen is found in period 2?
2. How many valence electrons does calcium have?
3. Why does the size of an atom increase moving down a group?
Octet rule – Atoms tend to gain, lose, or share electrons in order to acquire a full set of valence electrons (8)
- 2 for H, He, Li, Be, + B
notes page 6
As of today, you should have the following:
Families colored in (page 168)
Valence electrons marked
+1, +2, -1,-2, and -3 ions marked
Day 2 3-2
Add today:
Reactivity trend (front / back)
Atomic size (front / back)
Positive and negative ion trend on back
Day 2 3-2
Valence electrons =
2
1
3 4 5 6 7
8
Ions = +1
+2 -3 -2 -1
Atom size decreases
Atom
size increases
Reactivity increases away from the middle
Positive and Negative ion trendElements on the right side form negative ions.
Elements on the left form positive ions.