physical and chemical changes

Front

A copper penny turning greenish after a few years is an example of ...

Back

Chemical Change

Front

What is the common name for NaHCO₃?

Back

Baking soda

Answer explanation

Baking soda ( sodium hydrogen carbonate or sodium bicarbonate)

Front

Atomic number

Back

No. of electrons or protons in an atom

Front

Which of the following equation is correct?
1. 2 Mg+O₂→CO₂+MgO
2. Fe+O₂+H₂O→Fe₂O₃
3. MgO+H₂O→Mg+CO₂

Back

Fe+O₂+H₂O→Fe₂O₃

Front

In an atom, what is the number of protons equal to?

Back

the number of electrons

Front

Which of the following is a negatively charged subatomic particle? Options: Electron, Proton, Neutron, Quark

Back

Electron

Front

Burning always indicates a:

• Physical change
• Chemical change
• Periodic change
• Both physical and chemical change

Back

Chemical change

Front

Chemical formula for limewater

Back

Ca(OH)₂

Front

What fact is responsible for the long stability of the Iron pillar near the Qutub Minar in Delhi?

Back

It has not rusted after such a long period.

Front

Crystallisation is an example of

Back

reversible physical change