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Accounting for partnership:basic concepts

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Class 10 Class 12

What type of waves does light constitute?

Electromagnetic waves.

Atomic number is defined in terms of protons and not in terms of electrons. Why?

An atom may lose or gain electrons, but number of protons remain constant. Thus, it is defined as in terms of electrons.

Who proposed solar model of atom?


Give the range of wavelengths of visible light.

400nm to 800nm

The number of electrons, protons and neutrons in a species are equal to 18, 16 and 16 respectively. Assign the proper symbol to the species. 

The atomic number is equal to the number of protons = 16. The element is sulphur (S).
Mass No. = No. of protons + No. of neutrons
= 16 + 16 = 32.
Since the number of protons is not equal to the number of electrons, therefore the species is not neutral. It is anion (negatively charged) with charge equal to -2. Hence the symbol is space space straight S presubscript 16 presuperscript 32 superscript negative 2 end superscript.