Formative 3BC: Ionic v Covalent Bonds

Vanessa measures the melting points of four substances. She records the melting point of each substance in the table below. NaCl and KBr are ionic compounds. H₂O and C₆H₁₂O₆ are covalent compounds. How does Vanessa describe the difference between the melting points and elemental compositions of ionic and covalent compounds?

• Ionic compounds have higher melting points than covalent compounds. Ionic compounds are composed of all nonmetals while covalent compounds are composed of a metal and a nonmetal.

• Ionic compounds have higher melting points than covalent compounds. Ionic compounds are composed of a metal and a nonmetal while covalent compounds are composed of all nonmetals.

• 
  Ionic compounds have lower melting points than covalent compounds. Ionic compounds are composed of a metal and a nonmetal while covalent compounds are composed of all nonmetals.

• Ionic compounds have melting points that are similar to covalent compounds. Ionic compounds are composed of a metal and a nonmetal while covalent compounds are composed of all nonmetals.

Tags

NGSS.HS-PS1-1

What leads to the formation of a covalent bond?

• the transfer of electrons

• the sharing of an electron pair

• the transfer of protons

• the sharing of a proton pair

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NGSS.HS-PS1-2

A group of students is studying chemical bonds. They learned that electrons are shared between covalent bonds and transferred from one atom to another to form ionic bonds. They investigate the types of chemical bonds in five samples. During the first investigation, they test how long it takes for each sample to melt. During the second investigation, they test each the conductivity of each sample by connecting it to a circuit. The results of each test are recorded in the data table. Based on the observations from both investigations, which is the best conclusion for the type of bond for Sample 5?

• ionic bond, because it has a high melting point and could conduct electricity

• ionic bond, because it has a low melting point and could not conduct electricity

• covalent bond, because it has a high melting point and could conduct electricity

• covalent bond, because it has a low melting point and could not conduct electricity

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NGSS.HS-PS1-3

NGSS.HS-PS2-5

Which type of compound is usually formed when a metal reacts with a nonmetal?

• allotropic

• ionic

• covalent

• metalloid

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

Which of the following is a property of an ionic compound?

• 
  has a low boiling point

• forms molecules

• 
  is soft and flexible

• conducts electricity when aqueous

Which formula shows an ionic compound?

• MgH₂

• N₂O₄

• ClO₂

• SI₄

Tags

NGSS.HS-PS1-3

Which chemical formula represents a covalent compound because they share electrons?

• NaCl

• MgO

• CO₂

• KI

Which of the following is true for covalent bonding?

• electrons are shared

• oxidation numbers are always negative

• electrons are transferred

• particles are always positively charged

Covalent bonds take place between

• a metal and a nonmetal.

• a metal and a metalloid.

• two nonmetals.

• two metals.

An ionic bond takes place between

• 
  two metals.

• two nonmetals.

• a metal and a metalloid.

• a metal and a nonmetal.

Tags

NGSS.HS-PS1-3