9th Grade Science CA1 Revision Worksheet

Multiple Choice Questions

  1. What is the atomic number of Sodium?

    A) 11

    B) 23

    C) 19

    D) 12

  2. Which subatomic particle has no charge?

    A) Proton

    B) Electron

    C) Neutron

    D) Positron

  3. What is the maximum number of electrons in the second shell of an atom?

    A) 2

    B) 8

    C) 18

    D) 32

  4. Which group of the periodic table includes noble gases?

    A) Group 1

    B) Group 7

    C) Group 8

    D) Group 3

  5. Which element has the electronic structure of 2,8,8?

    A) Carbon

    B) Magnesium

    C) Argon

    D) Calcium

  6. As you go down Group 1 in the periodic table, what happens to the size of the atoms?

    A) Decreases

    B) Stays the same

    C) Increases

    D) Becomes unstable

  7. What is the trend in reactivity among Group 7 elements?

    A) Increases down the group

    B) Decreases down the group

    C) Stays constant

    D) Is unpredictable

  8. The melting point of which of the following increases as you go from fluorine to iodine?

    A) Fluorine

    B) Chlorine

    C) Bromine

    D) Iodine

  9. What is the name of the process where a liquid turns into a gas?

    A) Evaporation

    B) Condensation

    C) Precipitation

    D) Sublimation

  10. Which of the following is a property of alkali metals?

    A) They are good conductors of electricity

    B) They are all gases at room temperature

    C) They are highly stable

    D) They have a high melting point

Fill in the Blanks

  1. The number of
    __ in an atom equals the atomic number of that element.

  2. Electrons are found in specific energy levels or
    __ around the nucleus.

  3. The group number in the periodic table generally indicates the number of
    __ electrons an atom has.

  4. Elements in the same
    __ of the periodic table have similar chemical properties.

  5. The most reactive non-metals are found in Group
    __.

  6. Noble gases are characterized by their complete outer electron shells, making them largely
    __.

  7. The process by which a gas turns into a liquid is called
    __.

  8. Alkali metals react with water to produce hydrogen gas and a metal
    __.

  9. The periodic table is arranged by increasing
    __ number.

  10. Atoms of the same element with different numbers of neutrons are called
    __.

Open-Ended Questions

  1. Discuss the trends in reactivity and physical properties of the alkali metals as you move down Group 1. What implications do these trends have for their use in chemical reactions?

  2. Explain why noble gases are generally unreactive.

  3. Describe the difference between a physical change and a chemical change, providing an example of each.

  4. How does the arrangement of electrons in an atom determine its chemical properties?

  5. Discuss the significance of the atomic number and mass number in defining an atom.

  6. Compare and contrast the properties of metals and non-metals.

  7. Explain the concept of electronegativity and its trend across a period and down a group in the periodic table.

  8. Describe the process of ionic bonding, including the role of electron transfer.

  9. What are isotopes? How do isotopes of an element differ, and what are some common applications of isotopes?

  10. Elaborate on the periodic trends observed for atomic radius as you move across a period and down a group.

Answer Key
Multiple Choice Questions

  1. A

  2. C

  3. B

  4. C

  5. C

  6. C

  7. A

  8. A

  9. A

  10. A

Fill in the Blanks

  1. protons

  2. shells

  3. valence

  4. group

  5. 7

  6. unreactive

  7. condensation

  8. hydroxide

  9. atomic

  10. isotopes

Open-Ended Questions

  1. Responses will vary; students should discuss increasing reactivity, decreasing melting points, and possible applications in reactions.

  2. Responses will vary; students should mention full outer electron shells, stability, and lack of desire to gain/lose electrons.

  3. Responses will vary; physical change alters form but not composition (e.g., melting ice), chemical change forms new substances (e.g., burning wood).

  4. Responses will vary; students should discuss valence electrons, electron configuration, and tendency to achieve a stable octet.

  5. Responses will vary; atomic number defines the element (number of protons), mass number is protons + neutrons, which includes all subatomic particles in the nucleus.

  6. Responses will vary; metals are generally lustrous, malleable, ductile, good conductors of heat and electricity; non-metals are typically dull, brittle, poor conductors.

  7. Responses will vary; electronegativity is the ability of an atom to attract electrons in a chemical bond; it generally increases across a period and decreases down a group.

  8. Responses will vary; ionic bonding involves the transfer of electrons from a metal atom to a non-metal atom, forming oppositely charged ions that are attracted to each other.

  9. Responses will vary; isotopes are atoms of the same element that have the same number of protons but different numbers of neutrons, leading to different mass numbers. Applications include carbon dating and medical imaging.

  10. Responses will vary; atomic radius generally decreases across a period due to increasing nuclear charge pulling electrons closer, and increases down a group as new electron shells are added.

Notes

This worksheet is designed for 9th-grade students reviewing the properties of materials and the periodic table.

Students should work independently but can collaborate in pairs for open-ended questions to foster discussion.