EOT -2 G8 Science Quiz (2024) DSS

Calculate the number of neutrons in potassium-40 if the atomic number of potassium is 19.

• 20

• 21

• 59

• 50

The air in a hot -air balloon is heated which causes thermal expansion of air. The balloon rises up because, the density of the air inside the balloon is ______________ ___________ the density of air outside the balloon.

• a) lower than

• b) higher than

• c) equal to

• d) same as

The modern periodic table uses

• a) Moseley's arrangement of elements based on increasing atomic number

• b) Mendeleev's arrangement of elements based on increasing atomic number

• c) Moseley's arrangement of elements based on increasing atomic mass

• d) Mendeleev's arrangement of elements based on increasing atomic mass

Plasma, the fourth state of matter is made up of ____________________

• a) Electrons and other charged particles

• b) Atoms and Molecules

• c) Atoms and Ions

• d) Air and Space

Shamma used distillation method to separate a solution of salt and water. Referring to the image, identify, where the solids (salt) would be found after the distillation is complete?

• a) A

• b) B

• c) C

• d) A, B and C

Liquid Crystals

• a) lose their ordered arrangement when they change from a solid phase to a liquid phase

• b) do not lose their ordered arrangement completely when they change from a solid phase to a liquid phase

• c) do not lose their ordered arrangement completely when they change from a liquid phase to a gas phase.

• d) do not have any ordered geometric arrangement

Which of the following is true according to Charles's Law?

• a) At constant temperature, if the volume of a gas is increased, the pressure decreases.

• b) At constant temperature, if the volume of a gas is increased, the pressure increases.

• c) At constant pressure, if the temperature of a gas increases, the volume decreases

• d) At constant pressure, if the temperature of a gas increases, the volume increases

Maryam places a bottle of water in a freezer. She notices that the water expands on freezing. Which of the following statements is True?

• a) The expansion of water is an example of thermal expansion because the volume of water increases in the freezer.

• b) The expansion of water is not thermal expansion and is an exception (does not happen usually with other substances) as generally other substances do not expand on cooling

• c) The expansion of water is thermal contraction because substances contract on cooling

• d) Water does not expand on cooling

The graph in the image represents a graph of temperature vs time for heating 1.0 kg of water that undergoes changes in state at various temperature ranges. Which part(s) of the graph show constant temperature?

• a) AB and BC

• b) BC and CD

• c) CD and DE

• d) BC and DE

Carbon -12 and Carbon -14 are two isotopes of element carbon. This means that

• a) Mass number of carbon-12 is 12 and mass number of carbon -14 is 14

• b) Proton number of carbon-12 is 12 and proton number of carbon-14 is 14

• c) Atomic number of carbon 12 is 12 and atomic number of carbon 14 is 14

• d) Electron number of carbon 12 is 12 and neutron number of carbon 14 is 14