SCI-9 QUIZ

Which shows a correct description of ionic compounds and covalent compounds?

• o   Both ionic compounds and covalent compounds have low melting point.

• o   Both ionic compounds and covalent compounds have a high melting point.

• o   Ionic compounds have high melting points, covalent compounds have low melting points.

• o   Ionic compounds have low melting points, covalent compounds have high melting points.

What is the difference between a cation and an anion?

An anion has _____ one or more electrons, acquiring a _____ charge while a cation has _____ one or more electrons, having a _____ charge.  

• lost, negative: gained, positive      

• gained, positive: lost, positive

• gained, negative: lost, positive

• o   gained, positive: lost, negative

Ions are formed when atoms lost or gained electrons in order to fulfill the OCTET RULE and have full outer valence electron shells, to achieve stability. Which of the following statements accurately distinguishes positive ions from negative ions according to their tendency to gain or lose electrons?

• o   Positive ions lose electrons to comply with the Octet rule, negative ions gain electrons to comply with Octet rule.

• Both positive and negative ions gain electrons to comply with the Octet rule.

• o   Positive ions lose electrons to comply with the Octet rule, positive ions gain electron to comply with   Octet rule.

• o   Both positive ion and negative ions lose electrons to comply with Octet rule.

Evaluate which of the given statements below best describe the unique characteristics of carbon as an element?

I. Carbon atoms’ four valence electrons can be shared by different particles that have electrons to share, consequently   framing covalent (shared electron) bonds.

     II. Carbon atom has the ability to form long carbon-to-carbon chains.

     III. The carbon–carbon single bond is a sigma bond and is formed between one hybridized orbital from each of the        carbon atoms.

     IV. It can impart not just one electron to another atom to form a single bond, it can

        likewise share two or three electrons, framing a double or triple bond.

•   I and IV

• II and III

• I and II

• I, II, III, IV

Ethan is an 8-years old boy whose father works in a funeral as an embalmer. One day, he saw a bottle of formalin and asked his dad what is its use. What do you think Ethan’s father answered?

• o   It is used as antioxidant and source of vitamin

• o   It will be used as an insecticide and pest repellent

• o   It is used as a preservative in food, paints and cosmetics.

• o   It is used as a disinfectant in industries and embalming chemical in funeral homes.

This element is special and unique among the other elements because it can form many compounds not only with other elements.

• Nitrogen

• Hydrogen

• Carbon

• Sodium

How do molecular unit and formula unit differ?

            I. A molecule is composed of two or more elements that are covalently bonded.

            II. A formula unit indicates the lowest whole number ratio of ions in an ionic compound.

            III. Molecular unit is for ionic compounds while formula unit is for covalent compounds.

• I

• II

• I and II

• I, II, and III

How many valence electrons does carbon have?

• 4

• 2

• 6

• 8

How can we differentiate inorganic compounds from organic compounds? Which statement is incorrect?

• o   Organic compounds contain carbon-hydrogen bonds and inorganic compounds do not.

• o   Organic compounds are beneficial to the environment and inorganic compounds are not.

• o   Organic compounds are produced naturally, and inorganic compounds are human made.

• o   Organic compounds contain ionic bonds, and inorganic compounds contain covalent bonds.

The correct set of quantum numbers in the 3d sublevel.

• o   n = 2, l = 2, ml = -2, -1, 0, +1, +2, ms = -1/2 or +1/2

• o   n = 3, l = 1, ml = -2, -1, 0, +1, +2, ms = -1/2 or +1/2

• o   n = 3, l = 2, ml = -1, 0, +1, +2, ms = -1/2 or +1/2

• o   n = 3, l = 2, ml = -2, -1, 0, +1, +2, ms = -1/2 or +1/2