Unit 2 - Trends on the Periodic Table

NEW INFO: Why did Mendeleev organize his periodic table according to the atomic mass (instead of by atomic number)?

• He thought atomic mass was better!

• Atomic number had not been discovered.

• He did not want to organize them by atomic number.

• Who is Mendeleev?

Where are valence electrons located?

• outermost shell

• in the nucleus

• first shell

• They don't exist.

How many valence electrons are in Group 2 elements?

• 3 valence electrons

• 4 valence electrons

• 2 valence electrons

• 1 valence electrons

Group 1 elements are called

• Alkali Metals

• Noble gases

• Halogens

• Transition Metals

Group 7A elements are called

• Alkaline Earth Metals

• Halogens

• Transition Metals

• Noble Gases

A column of elements on the periodic table is called a ________ or family.

• Row

• Group

• Column

• Period

Elements of the same group have a similar number of what?

• protons

• electrons

• atomic pressures

• valence electrons

Which factor determines the chemical properties of an element?

• number of neutrons

• state of matter

• number of valence electrons

• period of the element

Why do we call the Noble Gases Noble?

• They react with everything.

• They don't react with other elements.

• They are very expensive.

• They need many valence electrons.

What is electronegativity?

• The ability of an atom to attract neutrons

• The ability of an atom to attract protons

• The ability of an atom to attract electrons