8Th Grade Physical Science-Unit 2 Study Guide

8th Grade Physical Science-Unit 2 study guide

Vocabulary

Protons

Neutrons

Electrons

Nucleus

Matter

Atomic number

Atomic mass

Mass Number

Isotope

Compound

Element

Heterogeneous mixture

Homogeneous mixture

Ionic bond

Covalent Bond Practice questions

1. What kind of charge does the nucleus have?

The nucleus has a positive charge because it contains the protons (+) and the neutrons (no charge)

2. Where is most of the atoms mass located?

A majority of the mass is located in the nucleus where the protons and neutrons are found. The protons and neutron are much larger than the electrons

3. What is the law of conservations of matter?

Matter cannot be created or be destroyed.

4. As fuel is burned in an airplane, it seems to disappear from the tank, suggesting that matter is destroyed during the reaction. Explain why this is not true

According to the law of conservation of matter, it cannot be created nor destroyed. In this example, the gas is merely changing states from a liquid to a gas.

5. Draw and label a carbon atom including; protons, neutrons and electrons. 6. How many protons does the atom have? 6

7. How many neutrons does the atom have? 6

8. How many electrons does the atom have? 6

9. What is the atomic number of the atom? 6

10. What is the mass number of the atom? 12

11. What is the number of valence electrons? 4

12. An atom with a neutral charge contains an equal number of ____Protons and Electrons______.

13. The mass of the nucleus contains which two particles? Protons and neutrons

14. The following appears in a chemical equation:

2CO2 How many carbon atoms?____2_____

How many oxygen atoms?__4_____

15. Glucose (C6H12O6) is a kind of sugar molecule. How many total atoms are in a molecule of glucose? 24

16. Which elements would you predict to have the most similar physical and chemical properties to Calcium? Atoms located in group 2 of the periodic table.

17. What number is most important in determining how an atom will bond? Valence electrons

18. What elements are most likely to form a compound with elements in row 2? Elements from group 16

19. Which group of elements has a full outer energy level containing eight electrons? Group 18, noble gases

20. What is helium’s atomic number? 18

21. What is helium’s symbol? ___He______

22. What is helium’s atomic mass? ___4.003____

23. How many of the following subatomic particles does helium have?

Protons____2__ Neutrons___2______Electrons___2______

24. Carbon has two three isotopes Carbon-12 and carbon-13 and carbon-14. For each of the isotopes, complete the chart below. (10 points)

Isotope Name Atomic Mass Number of Number of Number of number number Protons Neutrons electrons Carbon-12 6 12 6 6 6 Carbon-13 6 13 6 7 6 Carbon-14 6 14 6 8 6

25. Complete the chart using the periodic table provided to help you

Atomic Total number of Number of Number of Oxidation Element Symbol electrons valence electrons electrons lost or Number gain Iodine I 53 7 +(-1) -1 Lead Pb 82 4 +/- (-4) +/1 (-4) Strontium Sr 38 2 - (-2) 2 Hydrogen H 1 1 +/1 (-1) +/- 1