Question

physical science (chemistry & physics)

1. which particle has a negative charge?

a. proton b. neutron c. electron d. nucleus

1. which type of bond involves the transfer of electrons?

a. ionic b. covalent c. hydrogen d. metallic

1. water is a polar molecule because:

a. it has equal sharing of electrons b. it dissolves everything c. electrons are unevenly shared between hydrogen and oxygen d. its atoms are the same

1. which law states that matter cannot be created or destroyed in a chemical reaction?

a. law of stability b. law of conservation of mass c. newton’s first law d. law of thermodynamics

1. when an object accelerates, a net force must be:

a. zero b. balanced c. acting on it d. random

1. newton’s third law of motion states:

a. objects remain at rest unless acted on b. acceleration depends on force and mass c. every action has an equal and opposite reaction d. energy cannot be destroyed

1. kinetic energy depends on:

a. mass and velocity b. volume and density c. shape and color d. temperature and structure

1. which wave requires a medium to travel?

a. light wave b. radio wave c. sound wave d. gamma ray

1. which type of reaction releases energy by breaking down molecules?

a. endothermic b. exothermic c. synthesis d. neutralization

1. when two atoms share electrons, the bond is:

a. ionic b. covalent c. hydrogen d. nuclear
earth & space science

1. the movement of tectonic plates is driven by:

a. solar radiation b. convection currents in the mantle c. ocean tides d. wind patterns

1. earth’s seasons are caused by:

a. earth’s distance from the sun b. earth’s axial tilt c. changes in the atmosphere d. the moon’s gravity

1. which process is part of the rock cycle?

a. photosynthesis b. erosion c. dna replication d. protein synthesis

Explanation:

1. Protons are positively - charged, neutrons are neutral, and the nucleus is positively - charged as it contains protons. Electrons are negatively - charged.
2. Ionic bonds involve the transfer of electrons from one atom to another. Covalent bonds involve sharing, hydrogen bonds are intermolecular, and metallic bonds involve a sea of electrons in metals.
3. In a water molecule, electrons are unevenly shared between hydrogen and oxygen, making it polar.
4. The law of conservation of mass states that matter cannot be created or destroyed in a chemical reaction.
5. According to Newton's second law ($F = ma$), when an object accelerates, a non - zero net force must be acting on it.
6. Newton's third law of motion states that every action has an equal and opposite reaction.
7. The formula for kinetic energy is $KE=\frac{1}{2}mv^{2}$, so it depends on mass and velocity.
8. Sound waves require a medium to travel, while light waves, radio waves, and gamma rays can travel through a vacuum.
9. Exothermic reactions release energy by breaking down molecules. Endothermic reactions absorb energy, synthesis reactions build molecules, and neutralization is a specific type of reaction between acids and bases.
10. When two atoms share electrons, the bond is covalent. Ionic bonds are from electron transfer, hydrogen bonds are intermolecular, and nuclear bonds are within the nucleus.
11. The movement of tectonic plates is driven by convection currents in the mantle.
12. Earth's seasons are caused by Earth's axial tilt.
13. Erosion is part of the rock cycle. Photosynthesis is in plants, DNA replication is in cells, and protein synthesis is also a cellular process.

Answer:

1. C. Electron
2. A. Ionic
3. C. Electrons are unevenly shared between hydrogen and oxygen
4. B. Law of Conservation of Mass
5. C. Acting on it
6. C. Every action has an equal and opposite reaction
7. A. Mass and velocity
8. C. Sound wave
9. B. Exothermic
10. B. Covalent
11. B. Convection currents in the mantle
12. B. Earth’s axial tilt
13. B. Erosion