Atoms

What are atoms considered in chemistry?

• The fundamental building blocks

• A type of chemical reaction

• A form of energy

• A classification of molecules

How many kinds of atoms, or elements, have scientists discovered?

• 95

• 118

• Over 200

• Exactly 100

What did Democritus propose about matter?

• It is primarily empty space

• It is made of uncuttable particles

• It can be divided endlessly

• It is infinite

What did Marianne Paulze and Antoine Lavoisier conclude about certain pure substances?

• They can always be broken down further

• They are elements that cannot be broken down any further

• They can be created by mixing other chemicals

• They are all gases

What is a compound?

• A simple molecule

• A substance that cannot be broken down

• A substance formed from two or more elements

• A pure element

What did John Dalton's experiments suggest about elements?

• They are made of tiny, indivisible units called atoms

• They can be transformed into energy

• They are all the same size

• They are continuously divisible

What did Albert Einstein propose in 1905?

• A theory of relativity

• An experiment and equation to confirm the existence of atoms

• A model of the atom

• A method for splitting atoms

What technology allows us to 'see' atoms?

• Electron microscope

• Scanning tunneling microscope

• X-ray crystallography

• Optical microscope

What did the scanning tunneling microscope use to scan the surface of samples?

• Electron tunneling

• Sound waves

• Light waves

• Magnetic fields

How did scientists manage to use light to see atoms, despite its wavelength being much larger than an atom?

• By using a special type of light

• By cooling the atoms to near absolute zero

• By increasing the light's intensity

• By using a modified scanning tunneling microscope