chem quiz #1 study guide

Question 1

what is an atom?

Answer 1

◦ smallest particle of an element that CANNOT be divided/broken down

Question 2

how did Democritus characterize atoms?

Answer 2

he said that atoms are indestructible and indivisible

Question 3

how did Dalton advance the atomic philosophy proposed by Democritus

Answer 3

◦ by using experimental methods, Dalton transformed Democritus’ ideas on atoms into a scientific theory

short: he used experimental methods and turned Democritus’ ideas into a scientific theory

Question 4

why did Democritus’ approach lack experimental support?

Answer 4

◦ his approach was not based on the scientific method

Question 5

what instrument can be used to observe individual atoms?

Answer 5

scanning electron microscope

Question 6

Dalton’s atomic theory?

Answer 6

1. all elements are composed of atoms
2. atoms of the same element are the same while atoms of different elements are different
   (same atoms = same, diff = diff)
3. atoms in different elements can chemically combine/mix together in whole-number ratios
4. law of conservation of mass, chemical reactions occur when atoms are separated, joined, or rearranged

Question 7

explain why the ideas on atoms proposed by Dalton constitute a theory, while the ideas proposed by Democritus did not

Answer 7

Democritus’ beliefs were philosophical and had NO scientific evidence, while Dalton did

Question 8

what is the range of the radii of most atoms in nanometers?

Answer 8

5 × 10⁻¹¹ nm to 2 × 10⁻¹⁰ nm.

Question 9

according to Dalton’s theory, is it possible to convert atoms of one element into atoms of another?

Answer 9

no. atoms cannot be transformed into atoms of another element

Question 10

a sample of copper with a mass of 63.5 grams contain 6.02 x 10²³ atoms. calculate the mass of a single copper atom

Answer 10

1.05 x 10⁻²² g