Units 1 & 2 Quiz

9/10 A DAY, 9/11 B DAY - Significant Figures & Scientific Notation, Atomic History & Structure, Light & Energy

How many Significant Figures are in the number 100.25?

How many Significant Figures are in the number 100.25?

five

How many Significant Figures are in the number 0.00340 ?

three

Round 45730.2 to three significant figures.

45700

Round 0.0035071 to two significant figures.

0.0035

What is 450,000 in scientific notation?

4.5 × 10⁵

What is 0.000321 in scientific notation?

3.21 × 10^-4

What charge do protons have and where are they located?

positively-charged, located in the nucleus

What charge do neutrons have and where are they located?

neutral (no charge), located in the nucleus

What charge do electrons have and where are they located?

negative charge, located outside the nucleus

What does the atomic number tell us?

the number of protons an element has

How do you find mass number?

the sum of protons and neutrons

How do you calculate average atomic mass?

Avg. Atomic Mass = (mass 1 x abundance 1) + (mass 2 x abundance 2) + …

repeat for however many isotopes there are. remember to convert your abundances to decimals before calculating (divide by 100 or move decimal two spaces to the left)

What were the four postulates of Dalton’s Atomic Theory?

1. all matter is made up of atoms

2. atoms of an element are identical in size, mass, and other properties; atoms of different elements differ in size, mass, and other properties.

3. Atoms of different elements combine in simple whole-number ratios to form chemical compounds.

4. In chemical reactions, atoms are combined, separated, or rearranged.

What is the relationship between wavelength and frequency and energy?

An inverse relationship

long wavelength = low frequency = low energy

short wavelength = high frequency = high energy

What is the order of the electromagnetic spectrum from longest to shortest wavelength?

radio, microwave, infrared, visible, UV, x-ray, gamma

What is the order of the visible light spectrum from longest to shortest wavelength?

red, orange, yellow, green, blue, indigo, violet

the rainbow - ROY G BIV

What experiment did Rutherford conduct and what did he discover?

Gold Foil Experiment

discovered the positively-charged nucleus

What experiment did J.J. Thompson conduct and what did he discover?

Cathode Ray Tube Experiment

discovered electrons

Which atomic model did John Dalton create?

the Solid Sphere Model

Which atomic model did J.J Thompson create?

the Plum Pudding Model

Which atomic model did Rutherford create?

the Nuclear Model

Which atomic model did Bohr create?

the Planetary Model

Which atomic model did Schrödinger and Heisenberg create?

the Quantum (Cloud) Model