Atoms and Molecules — Science STD 9 — Question

State one condition necessary to liquefy gases (other than applying high pressure).

Which type of elements, metals or non-metals, show the property of brittleness?

What do we call those particles which have more or less electrons than the normal atoms?

Which of the following are not compounds?
Chlorine gas, Potassium chloride, Iron powder, Iron sulphide, Aluminium foil, Iodine vapour, Graphite, Carbon monoxide, Sulphur powder, Diamond.

Is alcohol is a mixture or a pure substance?

State two physical properties on the basis of which metals can be distinguished from non-metals.

Name the scientist who discovered electron.

The boiling point of alcohol is 78°C. What is this temperature on Kelvin scale?

Which single term is used to describe the mixing of copper sulphate and water kept in a beaker, on its own?

Out of honey or ink which will diffuse faster and why?