Periodic Table & Elements Unit Review

How are elements arranged in the periodic table?

• in alphabetical order
• in the order in which they were discovered
•  in order of increasing atomic number
•  in order of increasing melting points

The vertical columns in the periodic table are known as:

• groups
• periods
• valences
• isotopes

Group 18 of the periodic table contains nonreactive elements like helium, neon, and argon. The elements in this group are called:

• alkali metsls
• transition metals
• halogens
• noble gases

Why is the periodic table so useful to scientists?

•  it reminds them what the elements look like
• it can be used to predict how they react
•  it lists the chemical formulas for all of the different compounds
•  it contains the recipes for a variety of different kinds of mixtures

Every element in the period table:

• combines easily with other elements
• is a solid at room temperature
•  has atoms that are the same size
• has a unique set of properties

Use the periodic table to answer the question.
Which element listed below is a nonmetal?

•  sodium (Na)
•  magnesium (Mg)
• iron (Fe)
•  chlorine (Cl)

The periodic table is organized so that scientists can easily see:

•  the color of each element
• when each element was discovered
• the atomic number and atomic mass of each element
• the density and melting point of each element

The elements in the periodic table are placed in order based on:

•  the order in which they were discovered.
•  the number of protons in their atoms.
• the number of neutrons in their atoms.
•  the number of different isotopes they have.

The horizontal rows of the periodic table are known as:

• periods
• groups
• columns
• isotopes

 In their outermost energy levels, sodium has 1 electron, carbon has 4 electrons, fluorine has 7 electrons, and neon has 8 electrons. Which element is the least reactive?

• sodium
• carbon
• fluorine
• neon