Structure of the Atom — Science STD 9 — Question

The bond which never result in bond formation is:

A mixture of milk and ground oil can be separated by:

1. Sublimation.
2. Evaporation.
3. Separating funnel.
4. Filtration.

Which isotope is used in the nuclear power plants to generate electricity?

When a gas jar containing colourless air is kept upside down over a gas jar full of brown-coloured bromine vapour, then after sometime, the brown colour of bromine vapour spreads into the upper gas jar making both the gas jars appear brown in colour. Which of the following conclusion obtained from these observations is incorrect?

Mass number of all elements represents number of ______________?

For an element with atomic number 19, the 19th electron will occupy:

Which of the following does not have a fixed melting point/ boiling point?

3.42g of sucrose are dissolved in 18g of water in a beaker. The number of oxygen atoms in the solution are:

The number of valence electrons determines:

A homogeneous mixture is: