EHMS 8th Grade Final Exam Review 24-25

In which region of the table would nonmetals be found?

• 1

• 2

• 3

• 4

Tags

NGSS.HS-PS1-1

Nonmetals are classified based on their properties. The carbon element is classified as nonmetal because it displays the following properties...

• is shiny, conducts electricity and heat, and has a low melting point.

• is shiny, conducts electricity and heat and it has a high melting point.

• is dull, does not conduct electricity and heat and it has a low melting point.

• is dull, conducts electricity and heat, and has a high melting point.

Copper, Silver, and Gold are elements found on the periodic table. Tests involving these three elements would show that they are —

• highly conductive metals that exhibit excellent malleability and ductility

• poor conductors of electricity that are highly malleable and ductile

• highly conductive metalloids that are malleable and ductile

• all nonmetals that are malleable and conduct electricity

Tags

NGSS.2-PS1-1

Nitrogen and nitrogen-containing compounds are involved in many different reactions. Which balanced equation represents a reaction that involves 6 atoms of nitrogen?

• N₂ + 3H₂ → 2NH₃

• 4NH₃ + 3O₂ → 2N₂ + 6H₂O

• 3N₂ + 2O₂ → 2N₃O₂

Tags

NGSS.HS-PS1-7

Sodium bicarbonate, commonly known as baking soda or bicarbonate of soda, is a chemical compound with the formula NaHCO₃. How many different elements are in the compound sodium bicarbonate?

• 1

• 4

• 6

• 7

Students examined the properties of three different elements and recorded observations about their properties in the table. Based on the students' observations, classify each sample as a metal, nonmetal, or metalloid.

• Sample 2

• Nonmetal

• Sample 3

• Metalloid

• Sample 1

• Metal

Tags

NGSS.HS-PS1-1

The balanced equation below represents the reaction of NaOH with H3PO4. When 20 grams of NaOH reacts with 49 grams of H3PO4, 9 grams of water (H2O) is produced. How many grams of NaH2PO4 are produced?

• 11 grams

• 60 grams

• 69 grams

• 78 grams

Tags

NGSS.HS-PS1-7

Which of the following is a characteristic of ALL chemical changes?

• A. A different state of matter is produced.

• B. A new material is formed.

• C. Some mass is converted to energy.

• D. Some form of light is given off.

Tags

NGSS.HS-PS1-7

In making a pizza, which processes involve a chemical change? Select TWO correct answers.

• mixing spices such as salt and pepper for the sauce

• baking the dough to form the crust

• spreading three different cheeses on the pizza

• slicing circles of pepperoni for the topping

• placing the pizza in the oven having the cheese melt and the pepperoni become crispy

Tags

NGSS.HS-PS1-5

NGSS.HS-PS3-4

In the chemical reaction shown below, all of the HCl and Zn will react to form H₂ and ZnCl₂. Reactants: 2HCl (hydrochloric acid, liquid) + Zn (zinc, solid) Products: H₂ (hydrogen, gas) + ZnCl₂ (zinc chloride, solid) Which of the following statements describes the result of this reaction?

• The hydrogen gas will have a mass of zero

• The zinc chloride will have less mass than the zinc

• The mass of the products will equal the mass of the reactants

• The mass of the hydrogen atoms will decrease in the products

Tags

NGSS.HS-PS1-7