Unit 3.1 Exam Review - Periodic Table

Formula for Density

Density = Mass/Volume

Physical Properties of Metalloids

These elements have properties of both metals and nonmetals.

Chemical Property

A characteristic that can only be observed by destroying the substance; like rusting, corroding, or combusting.

Which group of metals is most reactive?

Alkali metals (Group 1) are most reactive because they only have one valence electrons.

What is the density of an object that has a mass of 15 g and the volume of 3 mL?

D = m/v = 15g/3mL = 5 g/mL

Which elements are most alike?

Elements in the same group or family look and react in similar ways because they have the same number of valence electrons.

Which group of nonmetals is most reactive?

Halogens (Group 17) are most reactive because they only need one valence electrons to complete their outer energy levels.

Which group of elements is least reactive?

The Noble Gases (Group 18) is inert due to the fact that the outermost energy level of these elements are full.

Density

The amount of matter in a given space or volume; a relationship between mass and volume

Valence Electrons

The electrons found in the outermost energy level of an atom that determine the reactivity of that atom.

Primary Arrangement of Elements on the Periodic Table

The first way that elements are arranged on the Periodic Table is by increasing atomic number. (The first element is Hydrogen with an atomic number of 1 and the last element is Meitnerium with an atomic number of 109.)

Groups (Families)

These elements are found in the same column. These elements have the same number of valence electrons therefore they look and react in similar ways.

Periods

These elements are found in the same row. These elements have the same number of energy levels. These elements DO NOT look or react in similar ways.

Physical Properties of Metals

These elements are malleable and ductile. They are good conductors of heat and electricity and have high melting points. Most are solid at room temperature and are shiny or have luster.

Physical Properties of Nonmetals

These elements are mostly dull, brittle solids or gases. They are poor conductors of heat and electricity, often called insulators and have a low melting point.

Atomic Number

This number represents that number of protons in each atom of an element.

Atomic Mass

This number represents the number of subatomic particles (protons and neutrons) in the nucleus of each atom of an element.

Physical Property

a characteristic that can be observed or measured without destroying the substance; like color, hardness, or boiling point.