The first artificial disintegration of an atomic nucleus was achieved by

• Geiger

• Wilson

• Madam Curie

• Rutherford

When any radioactive element emits β particle, some product is obtained. They both are

• isotopes

• isobars

• isomers

• isotoes

Electrical field is used to deflect

• α and β particles

• α and γ particles

• α,  β and γ particles

• β and γ particles

Meson was discovered by

• Yukawa

• Austin

• Moseley

• Einstein

The following element forms a molecule with eight of its own atoms

• Si

• S

• Cl

• P

The energy of an electron present in Bohr's second orbit of hydrogen atom is

• -1312 J atom^-1

• -328 kJ mol^-1

• -328 J mol^-1

• -164 kJ mol^-1

In the ground state, an element has 13 electrons in M shell. The element is

• copper

• chromium

• nickel

• iron

What is X in the following reaction ?

₁₂Mg²⁶ + ₁H² → ₁₂Mg²⁷ + X

• γ-ray

• ₀n¹

• ₁H¹

• ₁D²

99.

Which one of the following statements is not correct?

• Rydberg's constant and wave number have same units

• Lyman series of hydrogen spectrum occurs in the ultraviolet region

• The angular momentum of the electron in the ground state hydrogen atom is equal to $\frac{\mathrm{h}}{2\mathrm{\pi }}$

• The radius of first Bohr orbit of hydrogen atom is 2.116 × 10^-8 cm.

The energy of an electromagnetic radiation is 19.875 × 10^-13 ergs. What is its wave number in cm^-1? (h = 6.625 × 10^-27 erg sec; c = 3 × 10¹⁰ cm sec^-1)

• 1000

• 10⁶

• 100

• 10000