8th Grade Science Released Tests

The diagram above shows a block from the periodic table. The number six represents the —
1. atomic mass of the element carbon
2. atomic number of the element carbon
3. number of neutrons in the element carbon
4. number of valence electrons in the element carbon
Which of these belongs in the outermost shell (energy level) of an atom?
1. Electrons
2. Protons
3. Neutrons
4. Photons
Which of the following lists the elements in order, from those having the least protons to those having the most protons in the atoms?
1. O, N, B, Li
2. Na, S, Al, Cl
3. O, S, Se, Te
4. Rb, K, Na, Li
Which of these minerals is a carbonate?
1. Calcite (CaCO₃)
2. Galena (PbS)
3. Gypsum (CaSO₄)
4. Magnetite (Fe₃O₄)
Which of the following elements belongs to the family indicated?
1. Nitrogen belongs to the halogen family.
2. Helium belongs to the noble gas family.
3. Calcium belongs to the alkali family.
4. Sodium belongs to the alkaline earth family
Which of these elements has an atomic number of 14?
1. N
2. Al
3. Si
4. P
In the chemical formula for ammonia, , what does the subscript 3 represent?
1. The number of nitrogen and hydrogen atoms in each molecule of ammonia
2. The number of hydrogen atoms in each molecule of ammonia
3. The number of ammonia molecules that will bond together
4. The number of nitrogen atoms in each molecule of ammonia
According to this equation, what happened to the carbon and oxygen?
1. They combined chemically to form a new compound.
2. They combined chemically to form carbon and oxygen.
3. They combined physically to form a new mixture.
4. They combined physically to form a new element.
Calcium metal (Ca) can be produced by passing an electric current through molten calcium chloride (CaCl₂). Chlorine gas (Cl₂) is also formed. What is the balanced equation for this reaction?
1. 2CaCl → Ca + 2Cl
2. CaCl₂ + H₂O → Ca + ClH + O₂
3. CaCl₂ + Cl → Ca + Cl₃
4. CaCl₂ → Ca + Cl₂
Which of the following are products of combustion?
1. Heat and light
2. Newly discovered elements
3. Liquid and solid water
4. Additional atoms

8th Grade Science Released Tests - PS.4 Matter