Tip

A pure substance cannot be separated into its components, while a mixture can be separated.

A pure substance is always a gas, while a mixture can be a solid, liquid, or gas.

A pure substance is made up of only one type of substance, while a mixture is made up of multiple substances.

A pure substance is always a liquid, while a mixture can be a solid, liquid, or gas.

<P>A pure substance may contain subatomic particles but not atoms. </P>

<P>Atoms are the most basic form of matter. They combine to form larger electrically stable compounds.</P>

<P>Compounds are found inside the matter of atoms.</P>

<P>Compounds are the most basic form of matter. They combine to form larger atoms.</P>

<P>III and V</P>

<P>V</P>

<P>I and II</P>

<P>II and IV </P>

<P>They are heterogeneous materials because they do not have a uniform composition or appearance throughout.</P>

<P> These materials are homogeneous mixtures because they have a uniform composition throughout.</P>

<P>These can be either homogeneous or heterogeneous materials based on the individual solubility of each.</P>

<P>Elements and pure compounds are homogeneous materials because they have a uniform composition throughout.</P>

<P>remove the salt.</P>

<P>add sand.</P>

<P>boil the water.</P>

<P>add a small amount of sugar</P>

<P>Water molecules lose all contact with one another and intermolecular forces are non- existent.</P>

<P>Water molecules become less orderly and they spread apart.</P>

<P>The kinetic energy of the water molecules decreases proportionally to the temperature change</P>

<P>Water molecules separate into hydrogen and oxygen atoms.</P>

<P>The particles have sufficient energy to become an ionized gas and are in the most common state of matter in the universe.</P>

<P>The particles are bound through intermolecular forces but are able to move past each other with relative freedom.</P>

<P>The particles are not able to move out of their positions relative to one another, but do have small vibrational movements</P>

<P>The particles are not bound to one another, move quickly, have a low density, and are able to spread apart from one another if unconstrained</P>

<P>water, wood, neon gas</P>

<P>water, neon gas, wood</P>

<P>wood, water, neon gas</P>

<P>wood, neon gas, water</P>

<P>The density of a substance is the same regardless of the amount. </P>

<P>The rock was already wet from being submerged in the graduated cylinder of water.</P>

<P>The lake had become less dense because of heavy rains in the past month.</P>

<P> An object&apos;s density changes based on the amount of substance in which it is submerged.</P>

<P>1. Break the sample into a fine powder </P><P>2. Add the powder to a 500 mL beaker </P><P>3. Add 300 mL of water to the beaker and use to stirring rod to mix </P><P>4. Using a dropper, add 4 drops of universal pH indicator to the solution </P><P>5.Observe any color change in the sample </p><p>6. Record your observations</P>

<P>1. Create an acidic solution by adding 5 mL vinegar to 100 mL water </P><P>2. Place the sample into the acidic solution </P><P>3. Observe if the sample begins to fizz in the solution </p><p>4. Record your observations</P><P></P>

<P>1. Using tongs, hold the sample over a flame </P><P>2. Observe if the sample catches on fire </p><p>3. Record your observations</P>

<P>1. Place the sample in a resealable, zip-top bag </P><P>2. Firmly close the zip-top bag </P><P>3. Lightly tap the sample with a hammer </P><P>4. Observe if the sample dents, breaks, or shatters </p><p>5. Record your observations</P>

<P>B</P>

<P>A</P>

<P>D</P>

<P>C</P>

<P>Atom A has more protons than Atom B.</P>

<P> Atom A has an extra nucleon compared to Atom B.</P>

<P>Atom A has one more proton and one more electron than Atom B</P>

<P>Atom A has one less proton and one more neutron than Atom B.</P>

<P>solid to gas</P>

<P>metal to metalloid to non-metal</P>

<P>reactive to nonreactive</P>

<P>increasing number of outer-shell electrons</P>

<P>protons</P>

<P>neutrons</P>

<P>quarks</P>

<P>electrons</P>

<P>It is a chemical change because two different chemicals are mixed together.</P>

<P>It is a chemical change because heat energy is absorbed and the pack gets colder.</P>

<P>It is a physical change because the substance in the vial dissolved in the pack&apos;s liquid</P>

<P>It is a physical change as evidenced by a drop in temperature. </P>

<P> Ben is correct. It is a physical change and it is a solution, placing it in B. as a mixture.</P>

<P>They are both correct. It is a mixture and a compound and the contents should be placed in C.</P>

<P>Sam is correct. It is a chemical change and the contents should be in D. for compound.</P>

<P>Sam is correct. It is not a physical change and it should be placed in A. </P>

<P> temperature changes</P>

<P>chemical changes</P>

<P> phase changes</P>

<P>physical changes.</P>

<P>The students could repeat the experiment using different candles; there might have been a flaw in the candle</P>

<P>The students should burn the candle in a container that has some type of lid so that any gas that is a product of the reaction can be contained and massed.</P>

<P>The students should have someone in the class check their measurement skills as they repeat the experiment. They may have made an error using the balance.</P>

<P>The experiment should be repeatable. The students should run several trials and then take an average of the after mass in each trial.</P>

<P>16.5 grams</P>

<P>The mass cannot be determined without knowing the volume.</P>

<P>15.0 grams</P>

<P>13.5 grams</P>