8th Grade NC EOG Prep

What is a compound

• sodium

• sugar

• nitrogen

• air

Which is the best estimate of the melting point of Rubidium (Rb)?

• 25* C

• 40* C

• 75* C

• 184* C

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 escaped into the air.

• Some of the atoms during the reaction were destroyed.

• 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.

How does this 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 o the elements in Period 5 of the periodic table?

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

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

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

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

Which statement is true about a chemical reaction?

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

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

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

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

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

• group 1

• group 2

• group 16

• group 18

Which is the best example of a chemical change?

• butter melting

• egg cooking

• paper tearing

• water evaporating

Which chemical equation best represents the Law of Conservation of Mass?