Chemistry 4.1

Open Ended

How was Jon Dalton able to study atoms even though he couldn’t observe them directly? What evidence did he use to formulate his atomic theory?

Open Ended

How was Democritus’s idea of the atom different from Dalton’s?

Open Ended

If an atom has a radius of 1 ´ 10-10 m, how many of these atoms must be lined up in a row to produce a line 1 cm long?

Fill in the Blanks

the smallest particle of an element that retains its identity in a chemical reaction

Multiple Choice

Who was among the first to suggest the existence of atoms?

• Democritus

• Einstein

• Dalton

• Aristotle

Multiple Select

Select the 4 parts of Dalton's Atomic Theory

• All elements are composed of tiny indivisible particles called atoms

• Atoms of the same element are identical. The atoms of any one element are different from those of any other element

• Atoms of different elements can physically mix together or can chemically combine in simple whole-number ratios to form compounds

• Chemical reactions occur when atoms are separated from each other, joined, or rearranged in different combinations. Atoms of one element are never changed into atoms of another element as a result of a chemical reaction

• Atoms of different elements cannot physically mix together or chemically combine in simple whole-number ratios to form compounds