Q1 · easy · AI-verified
Which subatomic particle was discovered by J.J. Thomson through cathode ray experiments?
- Electron
- Neutron
- Positron
- Proton
Q2 · easy · AI-verified
The modern periodic table is based on the periodic law proposed by:
- Henry Moseley
- Dmitri Mendeleev
- John Newlands
- Lothar Meyer
Q3 · easy · AI-verified
The number of electrons in the outermost shell of an atom is called:
- Core electrons
- Inner electrons
- Nuclear electrons
- Valence electrons
Q4 · easy · AI-verified
An atom of phosphorus (P) has atomic number 15. How many electrons are present in its third shell?
- 3
- 7
- 8
- 5
Q5 · easy · AI-verified
Which of the following is the correct order of increasing atomic radius for the elements Na, Mg, Al, and Si (all in Period 3)?
- Mg < Na < Si < Al
- Si < Al < Mg < Na
- Na < Mg < Al < Si
- Al < Si < Na < Mg