Fall Semester Review

How many neutrons are in a potassium (K) atom with a mass number of 39? (M-A=N) (Subtraction)

• 19
• 20
• 39
• 40

The diagram shows the model of an atom. The model has 4 different symbols on it. In this diagram, which particle determines the reactivity of this atom?

• Particle Z
• Particle X
• Particle Y
• Particle W

The mass of the unidentified rock is 15.5 grams. The students find the volume of the rock by placing it in the cylinder with water. They determine the identity of the rock based on the density ranges in the table. The students most likely have what type of rock?

Density= Mass/Volume

• Coal
• Dolomite
• Peridotite
• Sandstone

(Law of Conservation of Matter:) Two solutions are mixed and react to produce the solid precipitate AgCl. The chemical reaction is shown by the balanced chemical equation. AgNO3 + NaCl → AgCl + NaNO3 What happens to the total mass as the reaction takes place?

• The mass stays the same
• The mass increases
• The mass decreases
• The mass first decreases then increases

The names and chemical formulas of 4 compounds are shown on the chart. Which substance shown in the chart is made up of the most atoms?

• carbonic acid
• nitric acid
• hydrochloric acid
• sulfuric acid

Which group of elements is often brittle and cannot be easily shaped into thin sheets or drawn into wires?

• Metals
• Noble metals
• Nonmetals
• Metalloids

Which category of elements generally are shiny and good conductors?

• Metals
• Noble metals
• Nonmetals
• Metalloids

Which category of elements is typically found on the left side and in the middle of the periodic table?

• Nonmetals
• Unknown
• Metalloids
• Metals

Where can valence electrons be found?

• In the outside energy level of an atom
• In the inner energy levels of an atom
• In the nucleus of an atom
• In the electron cloud surrounding an atom

Which piece of information would be most useful in identifying an atom?

• 15 electrons
• 14 neutrons
• 14 protons
• 2 valence electrons