Chemistry Unit 2

What happens to the mass of the reactants in a chemical reaction?

• The mass of the products gets larger.

• The mass of the products gets smaller

• The mass of the products does not change

• Products do not have mass

Tags

NGSS.MS-PS1-5

In the reaction Hydrogen peroxide yields oxygen gas + water, what are the products?

• Hydrogen peroxide, oxygen gas, and water

• Water and oxygen gas

• oxygen gas and hydrogen peroxide

• hydrogen peroxide

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

In the reaction Hydrogen peroxide yields oxygen gas + water, what are the reactants?

• Hydrogen peroxide, oxygen gas, and water

• Water and oxygen gas

• oxygen gas and hydrogen peroxide

• hydrogen peroxide

Tags

NGSS.MS-PS1-2

Suppose the mass of two reactants totals 15 grams.  After the chemical reaction, what should be the total mass of the products?

• 7 1/2 grams

• 30 grams

• 20 grams

• 15 grams

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

A typical atom of Uranium a has 92 electrons and 146 neutrons. How many protons does the atom have?

• 146

• 242

• 54

• 92

Elements are described as pure substances because

They can be produced in a laboratory

• They are all found in nature

• They cannot be separated into parts by physical means

• They have no charge

• They can be produced in a laboratory

The nucleus of an atom contains

choose all that apply

• electrons

• protons

• neutrons

• ONLY protons

made of only one kind of atom and cannot be broken down into simpler substances?

• molecule

• compound

• element

• mixture

The element hydrogen forms molecules that each contain two hydrogen atoms. The elements hydrogen and oxygen form molecules that each contain two hydrogen and one oxygen atoms, which of the following is true?

• both hydrogen and water are compounds

• hydrogen is an element while water is a compound

• hydrogen is a compound and water is an element

• neither hydrogen nor water is a compound

Tags

NGSS.MS-PS1-1

A teacher writes the equation representing the chemical reaction between hydrochloric acid and sodium on the board.

2HCl + 2Na → NaCl + H₂

The teacher states that the equation has not been balanced. Which of these correctly shows the products of this reaction after the equation has been balanced?

• Na₂Cl + H₂

• 2NaCl + H₂

• NaCl + 2H₂

• 2NaCl + 2H₂

Tags

NGSS.MS-PS1-5