Upload
oliver-joseph
View
234
Download
0
Tags:
Embed Size (px)
Citation preview
REVIEW: Parts of the Atom
ElectronElectron
OrbitOrbit
NeutronNeutron
ProtonProton
NucleusNucleus
Element, Compound, or Mixture?
ELEMENTELEMENT COMPOUNDCOMPOUND ELEMENTELEMENT
MIXTUREMIXTURE COMPOUNDCOMPOUND MIXTUREMIXTURE
Review of the Periodic Table
titanium22
47.867
What is the symbol for Titanium?
_________
What is the atomic number of titanium?
_________
How many protons does titanium have?
_________
How many electrons does a neutral titanium atom have?
__________
What is the atomic weight for titanium?
_______________
Ti
Ti
22
22
47.867
22
Author: J R Reid
The Periodic Table
The Periodic table as we know it today was arranged by a Russian Chemist named Mendeleev. He arranged it according to the physical and chemical properties of the elements
WORKSHEET 1
Complete the handout by writing the missing chemical symbols in each box.
ON your periodic table (given last lesson) Label the following:
AlkaliAlkaline MetalsTransition MetalsPoor metalsHalogensNoble gasesNon metals
halogens
Arranging Elements
It is arranged in rows (across) called Periods and columns (down) called Groups
Groups of elements show certain trends – they have similar properties
Groups
Periods
Author: J R Reid
Trends On The Periodic Table
Atomic Size
Atoms have certain sizes depending on:The amount of electrons (negatives)The pull from the nucleus (positive protons)
For the third period (row) the atomic radius for each atom gets smaller across the table
Even though the atoms have got more electrons their electronegativity (pull for electrons) is increasing because of increasing number of protons
Na Mg Al Si P S Cl Ar
Na Mg Al Si P S Cl Ar
Electronegativity
Electronegativity is the ability of a nucleus to attract its valence/bonding electrons. It follows certain trends on the table:
As you go across (left to right) it gets strongerAs you go up it gets stronger
e-e-
e- e-
e-e-
e-
e-
e-
e-
e-
e-e-
e-
e-11 12 13 14 15 16 17
K
e-
e-
e-
e-
e-
e-
e-
e-
What do you notice about the atomic number as you go across the period?
What about the number of orbitals as you go across the period?
What about the number of orbitals as you go down a group?
19
Increasing size Size
Trends From Left to Right
Proton number and Atomic Mass increasesAtomic size decreases (more protons pulling the electrons)
Oxidising ability increasesForm ionic compounds to forming covalent compoundsMelting Points from relatively high to relatively low Form positive ions to form negative ions
Trends down a group
Proton number and Atomic Mass increasesAtomic size increases (adding more orbitals)Metals become more reactiveNon-metals become less reactive
Valence Electrons
Valence electrons (also known as valence) are the number of electrons present in the outer most orbital.
What is the valence of this sodium atom?
What is the valence of this chorine atom?
Valence Electrons
The number of valence electrons of an element is determined by its periodic table group in which the element is categorized.