Complete the statement:

The octet rule states that atoms tend to form bonds so that each atom has eight

(a)   in its ​ (b)   shell.

• electrons
• valence
• inner
• protons
• neutrons

According to the octet rule, the number of chlorine ions that would bond with a calcium ion is

Which statement best describes a metallic substance

• Metals have low melting and boiling points and are brittle.

• Metals conduct electricity and can be hammered into different shapes.

Tags

NGSS.MS-PS3-3

Select the statement that best describes covalent bonds

• Covalent bonds result from metal atoms exchanging at least some of their valence electrons to form an octet.

• Covalent bonds form when atoms of nonmetals are close enough to each other for their orbitals to overlap resulting in shared electrons.

Tags

NGSS.MS-PS1-1

Which of the following Lewis structures for H₂O are correct? Select all that apply.

• 
• 
• 
• 

Tags

NGSS.MS-PS1-1

Organic chemists identified four different liquids of varying volatilities that they want to test further. They want to compare the overall volatility and intermolecular forces of these liquids. Look at the picture. For closed beaker, the circles indicate the amount of liquid volatility. A beaker with a large number of circles would have more liquid volatility than a beaker with only a few circles. Which option correctly ranks the liquids in the order of increasing intermolecular forces?

• II

• second WEAKEST intermolecular forces

• III

• WEAKEST intermolecular forces

• I

• STRONGEST intermolecular forces

• IV

• Second STRONGEST intermolecular forces

Which of the molecules has the highest boiling point?

• Liquid 1: CH₄

• Liquid 2: CH₃CH₃

• Liquid 3: CH₃CH₂CH₃

• Liquid 4: CH₃CH₂CH₂CH₃

Tags

NGSS.HS-PS1-3

Select the statement that best describes the difference between the compound Br₂ and the compound NaBr.

• The melting point of NaBr would be significantly HIGHER than that of Br₂ because NaBr is an ionic compound whereas Br₂ is a covalent compound.

• The melting point of NaBr would be significantly LOWER than that of Br₂ because NaBr is an ionic compound whereas Br₂ is a covalent compound.

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

Select the statement that best describes the difference between the compound O₂ and the compound K₂O

• K₂O would be a solid at room temperature because K₂O is an ionic compound whereas O₂ is a covalent compound.

• O₂ would be a solid at room temperature because O₂ is a covalent compound whereas K₂O is an ionic compound.

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

The melting point of CBr₄ suggests that it can be classified as an ionic compound.

• True

• False

Tags

NGSS.HS-PS1-3