MCQ
In helium nucleus, there are
  • A
    $2$ protons and $2$ electrons
  • B
    $2$ neutrons, $ 2$ protons and $2$ electrons
  • $2$ protons and $2$ neutrons
  • D
    $2$ positrons and $2$ protons

Answer

Correct option: C.
$2$ protons and $2$ neutrons
c
(c) Helium nucleus $→ _2H{e^4}$.
Number of protons $= Z = 2$
Number of Neutrons $= A -Z = 2.$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

The refractive index of water is $1.33.$ The direction in which a man under water should look to see the setting sun is
A $100 \,\,\Omega$ resistance and a capacitor of $100 \,\,\Omega$ reactance are connected in series across a $220\,\ V$ source. When the capacitor is $50\%$ charged, the peak value of the displacement current is.....$A$
Which of the following statements about the behaviour of light is not correct?
Two coherent monochromatic light beams of intensities $I$ and $4I$ are superposed. The maximum and minimum possible intensities in the resulting beam are :
Out of the following statements which is not correct
A wavefront presents one, two and three $HPZ$ at points $A, B$ and $C$ respectively. If the ratio of consecutive amplitudes of $HPZ$ is $4 : 3$, then the ratio of resultant intensities at these point will be
$A$ and $B$ are two radioactive substances whose half lives are $1$ and $2$ years respectively. Initially $10\, gm$ of $A$ and $1\, gm$ of $B$ is taken. The time (approximate) after which they will have same quantity remaining is ........... $years$
The electric field of plane electromagnetic wave of amplitude $2\,V/m$ varies with time, propagating along $z-$ axis. The average energy density of magnetic field (in $J/m^3$ ) is
When an electron strikes the target in a Coolidge tube, its entire kinetic energy:
A concave mirror and a converging lens (glass with $\mu  = 1.5$) both have a focal length of 3 cm when in air. When they are in water $\left( {\mu = \frac{4}{3}} \right),$ their new focal lengths are