Periodic Table trends: Chemistry

Explain why radius increases down a family

# of shells increase = electrons are farther from the protons = less pull

Explain why radius decreases across a period towards the nonmetals

# of shells is constant but the elements have more protons as you go to the right - this increases the pull on the outside electrons which causes the atoms size to decrease

What is a cation and how do they form?

+ charged ions, form by loss of electrons

Anions- what are they and how do they form?

- ions, form by gain of electrons

All Halogens will form a charge of

-1

All Alkali metals have _____ valence electrons and will form a charge of

1 valence e- and charge of +1

All Alkaline Earth Metals are in group # ______ and have ____ valence electrons

2A and have 2 valence electrons

All elements in group 6 have _____ valence electrons

6

Any atom with 7 valence electrons belong in group # ________ and which is also known as the ___________________

7A and are known as Halogens

All Noble Gases are in group _____have ____ valence electrons

8 8A and have 8 valence electrons

period

A horizontal row of elements in the periodic table

Name group with 8 valence electrons

All Noble Gases have ____ valence electrons

halogens properties and location

Contains nonmetals, 7 valence electrons in it's outermost energy level. Very reactive

nonmetallic properties

Dull, brittle, poor conductors

noble gases properties and location

Elements in group 8A of the periodic table. Have no charge and are gases under normal conditions. (Helium, Neon, Argon, Krypton, Xenon, Radon). Very Stable and unreactive

Families, Columns, Groups

Elements that are similar in properties are grouped in __________

Explain why Francium has the lowest ionization energy

Francium has 7 shells so its protons are very shielded and thus ineffective at holding onto the electrons. This makes it easy to remove electrons thus the energy is low.

alkali metals location and basic properties?

Group 1, 1 electron in outer level, very reactive, soft, silver, shiny, low density; Lithium, Sodium, Potassium, Rubidium, Cesium, Francium

What does the group number for the representative "A" elements tell you about the periodic table?

Group A Number = Number of valence electrons

radius

Half the distance between the centers of 2 of the same atoms OR the distance between the nucleus and valence electrons is known as the atomic _____

non-metals

Low conductivity, not ductile, brittle, dull, gas at room temp

octet rule

States that atoms lose, gain or share electrons in order to acquire a full set of eight valence electrons

ionization energy- definition

The amount of energy required to remove an electron from an atom

group

a vertical column in the periodic table that contains elements having similar physical and chemical properties

As you go from the left to the right across a period in the table, the atomic radius

decreases

As you go from the top to the bottom of a family, ionization energy

decreases

As you go from top to bottom of a group, ioniziation energy

decreases

families

elements with similar properties located in same group or column.

Nonmetals _____ electrons to become stable and become _____

gain, anions (-)

Elements with same properties are found within the same ______________ why?

group or column because they have the same number of valence electrons.

metals properties

have a shiny or metallic luster, good conductors of heat and electricity

periods definition

horizontal rows on periodic table of elements

As you go down a family of metals, the reactivity ________

increases

As you go down a family of nonmetals, the reactivity _________

increases

As you go from the left to the right across a period, ioniziation energy

increases

As you go from the left to the right across a period, the electronegativity

increases

As you go from the top to the bottom in a group, the atomic radius

increases

As you go from the left to the right across a period, ioniziation energy __________________

increases- size decreases so valence electrons closer to nucleus and more tightly held, harder to remove.

If an atom has 5 valence electrons what will it do to become stable? What will it form?

it will gain 3 electrons to get to the octet. It will form an anion with a charge of 3-.

Metals ______ (gain or lose)electrons to become stable and form _____.(Cations or Anions)

lose, cations (+)

alkaline earth metals properties and location

metallic elements in group 2 of the periodic table which are harder than the alkali metals and are also less reactive

The periodic table is made up mostly of which type of element?

metals

What does the period number tell you about atomic structure?

period number = # of Energy levels

Label the charges that each representative group will form above the column on a periodic table.

periodic table charges

malleable- description

property of metals - meaning they can be hammered into thin sheets and bent

transition elements

the elements most likely to form more than one type of ion and located in the three rows of elements in the middle of the periodic table are known as the ____________ elements. The "B" groups

groups definition

vertical columns on periodic table of elements