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The Greek philosopher Democritus coined what word for a tiny piece of matter that cannot be divided?

• Electron

• Molecule

• Element

• Atom

What is the most important safety rule?

• Never do experiments that involve flames or hot objects.

• Never work with chemicals.

• Always follow your teacher's instructions and lab directions exactly.

• Always used unbreakable glassware

Which of the following is a chemical change?

• Water breaking down in hydrogen and oxygen

• ice being carved

• ice melting

• water boiling

Which lists of elements contains only metals?

• Helium, iron, copper

• Tin, copper, gold

• Carbon, iodine, tin

• Iodine, carbon, argon

Rutherford's gold foil experiment provided evidence for which of the following statements?

• Alpha particles have a positive charge.

• There is a dense, positively charged mass in the center of an atom.

• Gold is not as dense as previously thought.

• Negative and positive charges spread evenly throughout an atom.

Which of the following is malleable?

• Pottery

• Ice

• Gold

• Glass

The smallest unit of an element that maintains the properties of that element is a(n)

• Atom

• Compound

• Substance

• Molecule

Atoms of the most reactive elements tend to have

• No valance electrons

• Eight valance electrons

• One or seven valance electrons

• Four or five valance electrons

Which of these elements would most likely be shiny, gray-colored, solid at room temperature, conduct electricity, and dent when hit with a hammer?

• Argon

• Aluminum

• Sulfur

• Chlorine

Which of the following is NOT a pure substance?

• Milk

• Water

• Carbon dioxide

• Oxygen