Science Challenge for Class 10

What is the chemical formula for water?

• H2O2

• CO2

• H2O

• NaCl

Define Newton's first law of motion.

• An object will remain at rest or in uniform motion unless acted upon by an external force.

• An object will accelerate if no force is applied.

• An object will change direction only when a force is applied.

• An object will remain in motion only if it is in a vacuum.

What is the process of photosynthesis?

• Photosynthesis is the process by which plants convert light energy into chemical energy, producing glucose and oxygen from carbon dioxide and water.

• Photosynthesis is the way in which plants breathe in carbon dioxide and release nitrogen.

• Photosynthesis is the method by which animals convert food into energy.

• Photosynthesis is the process of plants absorbing nutrients from the soil.

Name the three states of matter.

• solid, liquid, gas

• plasma, vapor, foam

• solid, liquid, plasma

• gas, liquid, crystal

What is the pH value of pure water?

• 6

• 5

• 8

• 7

Explain the law of conservation of mass.

• The total mass of products is always less than the mass of reactants.

• Mass is only conserved in physical changes, not chemical changes.

• Mass can be created in chemical reactions.

• Mass is conserved in chemical reactions; total mass of reactants equals total mass of products.

What is the main function of the respiratory system?

• To facilitate gas exchange (oxygen and carbon dioxide) between the body and the environment.

• To filter and purify blood before it circulates.

• To produce hormones that control metabolism.

• To regulate body temperature through sweating.

Describe the structure of an atom.

• An atom is structured with a central nucleus made of protons and neutrons, surrounded by orbiting electrons.

• An atom consists only of electrons in a cloud without a nucleus.

• An atom is a solid particle that cannot be divided into smaller parts.

• Atoms are made up of only protons and electrons, with no neutrons present.

What is the difference between speed and velocity?

• Velocity measures distance only.

• Speed is scalar; velocity is vector (includes direction).

• Speed is always greater than velocity.

• Speed includes direction, while velocity does not.

What are the primary components of blood?

• Muscle cells, nerve cells, and fat cells

• Red blood cells, white blood cells, platelets, plasma

• Nutrients, oxygen, and carbon dioxide

• Red blood cells, white blood cells, and hormones