7.6B, 8.6B & 8.6E Quizizz Questions

What do scientists use to identify the elements present in a molecule?

• chemical symbol

• subscript

• elements in Group 18

• chemical formula

When do we use parentheses in a chemical formula?

• any time there is a subscript

• only when we have a coefficient

• when there is a special subgroup of atoms

• whenever there is an invisible “1”

What does a subscript tell us?

• how many atoms of each element are in a molecule

• the charge of the ion

• the amount of molecules in a reaction

• the atomic number of the element

What are chemical formulas made up of?

• electrons and coefficients

• chemical symbols and subscripts

• molecules and elements

• atoms and electrons

If there is no number after a chemical symbol, how many atoms of that element are there?

• 0

• 1

• 2

• We do not know how many.

When are parentheses needed in a chemical formula?

• never

• always

• to group certain atoms together

• when there is an invisible “1”

What inspired Dmitri Mendeleev to create the periodic table?

• He wanted to win a scientific competition.

• He noticed patterns and connections among elements.

• He was trying to create a new type of element.

• He was following the instructions of his professor.

Elements in the same group have what in common?

• chemical properties

• physical properties

• atomic mass

• atomic number

What are the horizontal rows in the periodic table called?

• groups

• columns

• periods

• families

Which reaction involves elements from Group 2 and Group 16?

• H2​ +Cl2​ → 2 HCl

• Na+Cl2 ​→ 2 NaCl

• 4 Fe+3O2​ → 2 Fe2​O3​

• 2 Ca+O2​ → 2 CaO