Chemistry Questions

The vast amount of sea weeds present in oceans may produce an endless source of

Find the similarity in the following :

Carbon, Silicon, Boron, Arsenic

Which one of the following statements would be INCORRECT to use?

Plaster of Paris ______.

I. changes into gypsum on mixing with water

II. is CaSO4.2H2O

III. is used for decoration

Isotopes have ______.

I. similar physical quantities and different chemical properties

II. different physical properties

III. similar chemical properties

Apart from proposing atomic theory, what did John Dalton researched on?

Which of the following statements are CORRECT?

I. Oxides of metals are generally basic.

II. Oxides of non-metals are generally acidic.

III. Non-metals are generally electro positive.

____ are atoms/molecules/ions containing the same number of electrons.