Chemistry Review Adams

What is a compound?

• Sodium

• Sugar

• Nitrogen

• Air

Two different liquids are poured together in an open container. Bubbles begin to form. After the bubbling stops, it is determined that the total weight of the two liquids is less than before they were poured together. Which best describes this observation?

• Some of the atoms during the reaction were destroyed

• Some of the atoms during the reaction escaped into the air.

• Some of the atoms during the reaction became heavier.

• Some of the atoms during the reaction changed to a different kind of atom.

This is a chemical reaction for the decomposition of carbonic acid into water and carbon dioxide.

H2CO3 → H2O + CO2

How does the reaction support the Law of Conservation of Mass?

• Several molecules of water are produced.

• The mass of carbon atoms is reduced during the reaction.

• The mass of the atoms in the reactant equals the mass of the atoms in the products.

• The mass of hydrogen atoms is the only thing that remains the same before and after the reaction.

Which is classified as an element?

• carbon dioxide

• iron

• vinegar

• water

Which best describes the sequence of the elements in Period 5 of the periodic table?

• nonreactive gases, metalloids, nonreactive metals, highly reactive metals, highly reactive gases

• highly reactive gases, relatively nonreactive metals, metalloids, very nonreactive gases, nonreactive nonmetals

• nonreactive gases, nonreactive metals, highly reactive metals, metalloids, reactive nonmetals, reactive gases

• highly reactive metals, relatively nonreactive metals, metalloids, reactive nonmetals, nonreactive gases

Which statement is true about a chemical reaction?

• All of the atoms in the reactants will be a part of the products.

• Some of the atoms in the reactants will be a part of the products.

• The physical states of the atoms in the reactants determine the products.

• The number of atoms in the reactants determines the products.

Chlorine has 7 valence electrons. With what group of elements will chlorine most readily bond?

• group 2

• group 16

• group 18

• group 1

Which is the best example of a chemical change?

• egg cooking

• butter melting

• water evaporating

• paper tearing

Which is the best example of a pure substance?

• milk

• peanuts

• air

• gold

Which statement best explains how periods on the periodic table are organized?

• decreasing number of electrons from left to right

• increasing number of neutrons from left to right

• decreasing atomic mass number from left to right

• increasing atomic number from left to right