Chemistry Unit Test Study Guide

How is an atom different from a molecule?

• An atom is a single unit of an element, while a molecule is a group of atoms bonded together.

• An atom is a group of molecules bonded together, while a molecule is a single unit of an element.

• An atom and a molecule are the same, with no differences.

• An atom is larger than a molecule.

What are the charges and roles of each subatomic particle in an atom?

• Proton - positive charge; determines identity of the atom. Neutron - no charge/neutral; holds the nucleus together. Electron - negative; responsible for reactivity.

• Proton - negative charge; responsible for reactivity. Neutron - positive charge; determines identity of the atom. Electron - no charge/neutral; holds the nucleus together.

• Proton - no charge/neutral; holds the nucleus together. Neutron - negative charge; responsible for reactivity. Electron - positive charge; determines identity of the atom.

• Proton - positive charge; responsible for reactivity. Neutron - negative charge; holds the nucleus together. Electron - no charge/neutral; determines identity of the atom.

What elements are in glucose (SUGAR)? What is its chemical formula? How many atoms of each element are in glucose?

• Carbon - 6 atoms, Oxygen - 6 atoms, Hydrogen - 12 atoms. Chemical formula: C6H12O6.

• Carbon - 5 atoms, Oxygen - 5 atoms, Hydrogen - 10 atoms. Chemical formula: C5H10O5.

• Carbon - 6 atoms, Oxygen - 12 atoms, Hydrogen - 6 atoms. Chemical formula: C6H6O12.

• Carbon - 12 atoms, Oxygen - 6 atoms, Hydrogen - 6 atoms. Chemical formula: C12H6O6.

Why is a salt crystal cubic in shape?

• Because of the spherical shape of sodium and chloride ions

• Due to the extended structure of salt molecules arranging themselves in a repeating pattern

• Because of the hexagonal packing of ions

• Due to the random arrangement of ions

What is the difference between a physical and chemical property? (pg. 21)

• Physical properties can be observed without changing it into another substance, while chemical properties is the ability to change into a different substance through a chemical reaction.

• Physical properties involve changes in the chemical composition of a substance, while chemical properties do not.

• Physical properties are always visible, while chemical properties are not.

• Physical properties are related to the substance's mass, while chemical properties are related to its volume.

What determines a substance's unique physical and chemical properties?

• Determined by a substance molecular formula and structure (composition)

• The temperature and pressure conditions

• The amount of substance present

• The color and texture of the substance

Write out a chemical reaction from our notebook and draw a circle around the products. Draw a box around the reactants. (pg. 25)

What happens to chemical bonds during a chemical reaction?

• They are created.

• They are destroyed.

• They are both created and destroyed.

• They remain unchanged.

What is the difference between a physical and chemical CHANGE? (pg. 25)

• Both physical and chemical changes alter the substance's identity.

• A physical change alters the substance's identity, while a chemical change alters only the form of a substance.

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  A physical change alters the form of a substance, not its identity, while a chemical change alters the substance's identity.

  
  

• Neither physical nor chemical changes alter the form or identity of a substance.

What are 5 pieces of evidence of a chemical change (reaction)?

• Color change, temperature change, gas production, sound emission, and odor change

• Color change, temperature change, bubbles of gas, precipitate formation, and change in taste/smell

• Color change, temperature change, gas production, precipitate formation, and sound emission

• Color change, temperature change, gas production, odor change, and light emission