Chemistry

Question 1

1Bohr's model of the atom proposed that electrons

Easy

A. are spread evenly like a pudding B. are inside the nucleus C. have no charge D. move in fixed energy levels (shells)

Question 2

2The scientific method begins with

Easy

A. publishing results B. a conclusion C. observation and asking a question D. a law

Question 3

3The quantum number that describes the shape of an orbital is the

Hard

A. principal quantum number B. magnetic quantum number C. spin quantum number D. azimuthal (l) quantum number

Question 4

4A sodium atom has atomic number 11 and mass number 23. How many neutrons does it have?

Easy

A. 23 B. 12 C. 11 D. 34

Question 5

5The maximum number of electrons in the n = 3 shell is

Hard

A. 32 B. 2 C. 18 D. 8

Question 6

6The number of protons in an atom is its

Easy

A. isotope number B. mass number C. valency D. atomic number

Question 7

7Chlorine is 75% chlorine-35 and 25% chlorine-37. What is its relative atomic mass?

Easy

A. 35.5 B. 35 C. 36 D. 37

Question 8

8Which particle has a relative charge of −1 and almost no mass?

Easy

A. nucleus B. proton C. electron D. neutron

Question 9

9The scientist who discovered the electron was

Easy

A. John Dalton B. Niels Bohr C. James Chadwick D. J. J. Thomson

Question 10

10Dalton's atomic theory stated that atoms

Easy

A. are divisible into electrons only B. are always charged C. cannot be created or destroyed in a chemical reaction D. are made of quarks