Sound — Science STD 9 — Question

Which of the following do not exhibit Tyndall effect?
Starch solution, Sugar solution, Ink, Salt solution, Copper sulphate solution, Ammonium chloride solution, Fog, Smoke, Car exhausts.

Out of a colloid, solution and a suspension:
Which one has the largest particles?

In which medium, air or water, an echo is heard much sooner? Why?

Explain why, the atomic masses of many elements are in fractions and not whole numbers.

State whether the following statement is true or false:
Earth moves round the sun with uniform velocity.

State whether force is a scalar or a vector quantity.

What is the condition for a force to do work on a body?

What is the most common way of expressing the concentration of a solution?

Name the property of bodies (or objects) to resist a change in their state of rest or of motion.

Name two gases which are supplied in compressed form in homes and hospitals.