Chemical Formulas and the Periodic Table

Which statement best distinguishes a molecular formula from an empirical formula?

• Shows the simplest whole-number ratio of atoms

• Shows actual numbers of atoms in a molecule

• Shows average mass of a single atom in nature

• Shows only the types of elements without ratios

Acetylene has the molecular formula C2H2. What is its empirical formula?

• C2H2

• CH2

• CH

• C2H4

Glucose has the molecular formula C6H12O6. Which empirical formula is correct?

• C3H6O3

• CH2O

• C6H12O6

• CHO

Using the data H = 1.008, C = 12.01, O = 16.00, what is the molar mass of CH2O?

• 44.01 g/mol

• 16.04 g/mol

• 30.03 g/mol

• 29.02 g/mol

In the phosphorus oxide example, the empirical formula is P2O2 and the molecular mass is twice the empirical mass. What is the molecular formula?

• P4O10

• P2O5

• P4O4

• P2O2

Which description matches the term atomic mass as shown on the periodic table?

• Exact mass of a single isotope only

• Sum of protons minus electrons count

• Average mass of an atom of an element

• Mass of the nucleus only in kilograms

Match each scientist or concept to the correct description.

• Arranged elements by atomic number

• John Newlands

• Father of the periodic table

• Dmitri Mendeleev

• Made triads of similar elements

• Henry Moseley

• Proposed the law of octaves

• Johann Dobereiner

In the periodic table structure, what are groups and periods?

• Groups are blocks; periods are families

• Groups are diagonals; periods are blocks

• Groups are columns; periods are rows

• Groups are rows; periods are columns

Match each group number with the correct family name.

• Alkaline earth metals

• Group 2

• Halogens

• Group 18

• Noble gases

• Group 17

• Alkali metals

• Group 1

Which pairing correctly identifies a bond type with the elements that usually form it?

• Ionic bond forms between two nonmetals

• Covalent bond forms between two metals

• Ionic bond forms between nonmetal and nonmetal

• Metallic bond forms between metal and metal