NAME:___________________________ Chemistry Test #2 REVIEW 1.What charge do atoms have? Explain

2.The isotopic symbol for beryllium, 94 Be, indicates what? Indicate all information possible:

3.What information was concluded from Rutherford’s gold-foil experiment?

4.List the principles of Dalton’s theory?

5.An atom of potassium has 19 protons and 20 neutrons. What is its mass number?

6. What does the atomic mass of an element represent?

7. Is atomic mass the same as mass number? Explain

8.Who first proposed the notion of the atom?

9.Which features of Dalton’s atomic theory are different from modern atomic theory? Explain

10.Which subatomic particle has essentially no mass?

11. Chlorine has two natural isotopes, chlorine-35 (34.97 u) and chlorine-37 (36.97 u), whose relative abundances are 75.8% and 24.2%. Calculate the average atomic mass of chlorine?

12. Hydrogen has three isotopes. hydrogen-1, hydrogen-2 and hydrogen-3. Which isotope is the most

abundant? Explain

13. Why did Thomson’s discovery of the electron mean that new hypotheses needed to be developed to

explain atoms? A It showed that the atom was made up of smaller particles. B It showed that the atom has an electric charge. C It showed that atoms are not the basic component of an element. D It showed that atoms have a nucleus surrounded by electrons.

14. How many electrons does a P-3 ion have?

15. What is the mass number of this element pictured below?

16. Which of the following would be an isotope of

a.)

X

c.)

55 26 56

b.) 24X

d.)

17. Define the following:

a. Atom b. Isotope c. ion

82 25 26 56

X

X

56

26X?

18. Arrange the scientists involved in the discovery of the atom in chronological order, from the first discovery to the modern day view of the atom.

19. Define each of the following: Model :

Law:

Hypothesis:

Theory

20. How many neutrons are present in isotope of Bromine-81

21. Draw 2 depictions of the following isotopes: include # of p+, # of e- and # of n and energy levels Carbon -12

carbon -14

22. Fill in the info below: # of valence e

name of group

halogens

6 1

charge attained when stable +2