What is the biggest difference between an atom of cobalt (Co) and an atom of nickel (Ni) as shown in the periodic table entries?

• An atom of nickel has more protons.
• An atom of cobalt has more electrons.
  
• An atom of cobalt has a lower number of neutrons.
  
• An atom of nickel has a higher value for atomic mass.

Tags

NGSS.MS-PS1-1

Charles needs a very lightweight metal. Use the periodic table to determine which he would choose.

• silicon
• magnesium
• iondine
• tungsten

Tags

NGSS.MS-PS3-1

In what order are the regions arranged on the periodic table, reading left to right?

• inert gases, metals, nonmetals, metalloids
• metalloids, metals, nonmetals, inert gases
• metals, metalloids, nonmetals, inert gases
• nonmetals, inert gases, metals, metalloids

Tags

NGSS.HS-PS1-1

Fluorine, chlorine, bromine, iodine, and astatine make up Group 17, the halogens. Why are these elements grouped together?

• They are all very reactive nonmetals with similar chemical properties.
• They are all nonreactive gases with similar physical properties.
• Their atoms all have eight electrons in their outer energy levels.
• They all have the same atomic number.

Which of the following best describes the properties of metals?

• hard, brittle, and nonconductive
• liquid, dark, and conductive
  
• shiny, malleable, and conductive
• soft, oily, and very reactive

How are the elements in the periodic table arranged?

• by their atomic mass
• by their chemical symbol
• by their chemical name
• by their atomic number

The graph above shows the densities in kilograms per cubic meter (kg/m3) of the elements in Period 2 of the periodic table. Given a 100m3 sample of each element in Period 2, which sample would have the greatest mass?

• the sample of Aluminum (Al)
• the sample of Chlorine (Cl)
• the sample of Sulphur (S)
  
• the sample of Argon (Ar)

What does the number of electrons in the outer level indicate about the element?

• how reactive the element is
• how malleable the element is
• how brittle the element is
  
• how ductile the element is

According to its location on the periodic table, sodium (Na) can be described as

• an alkaline-earth metal.
• a transition metal.
  
• an alkali metal.
  
• a metalloid.