Fundamental particles of an atom - class-XI

$(B)$ a helium nucleus 

The number of protons in an atom determines what element you have. For instance hydrogen has one proton, carbon has six.

Atomic number is equal to number of protons i.e. 8. Since number of protons is equal to number of electrons i.e. 8, therefore charge on the atom is 0.

The charge on protons is equal to $1.602\times10^{-19}C$

Elements are defined by the number of protons they possess.

The mass of proton is equal to $1.672\times10^{-27}$ kg.

The mass of an electrons is $9.109\times10^{-31}$ kg.

The mass of neutrons is $1.674\times10^{-27}$ kg

Equal number of negatively charged electrons and positively charged protons would give a neutral atom which would thus not have any electric charge.

The atomic number is the number of protons in an atom of an element. The atomic number of calcium in the periodic table is 30 and hence calcium has 30 protons in its nucleus.

Option $C$ is the correct answer.

A neutron is electrically neutral particle. And its mass is 1 amu or $ {1.67} $ $ {\times} $ $ {10}^{-27} $ Kg

Option $C$ is the correct answer.

Isotopes are atoms with the same number of protons but that have a different number of neutrons.

For nitrogen; atomic number = 7 and mass number = 14 

Neutron is not present in hydrogen. Electronic configuration of hydrogen is 1 $( _1H^1)$.

Mass of proton = $1.6\times 10^{-27}$kg and mass of electron = $9.1\times 10^{-31}$kg
$\therefore\dfrac{\text{mass of proton}}{\text{mass of electron}} = \dfrac{1.6\times 10^{-27}}{9.1\times 10^{-31}} = 1.8\times 10^{3}$

$M^{2+}=2, 8, 14;\Rightarrow $ Electronic Configuration of $M=2, 8, 16$
So. total electrons in M will be $=26$
i.e., atomic number $(Z)=26$, Mass number (given) $=56$
$\therefore$ Number of neutrons$=A-Z=56-26=30$

Molar mass of oxygen we know is $32$g.

Normality=$n\times Molarity$

14g of N2 gas is 0.5 moles (molar mass 28g/mol). Each N2 molecule has 14 electrons (7 per nitrogen atom), so 0.5 moles of N2 contains 0.5 * 6 * 10^23 * 14 = 4.2 * 10^24 electrons.

C-12 has 6 protons and 6 neutrons. Si-30 has 14 protons and 16 neutrons (30 - 14). The ratio of neutrons is 6:16, which simplifies to 3:8.

Electronic configuration of copper is- $1s^22s^22p^63s^23p^64s^13d^{10}$

Mass of one electron $=9.1\times 10^{-27} g $

Rest mass of an electron is $9.11\times 10^{-31}kg$.
So, mass of one mole of electron is $9.11\times 10^{-31}\times6.023\times10^{23} = 5.5\times 10^{-7}kg/mole$

A nucleon is one of either of the two types of subatomic particles (neutrons and protons) which are located in the nucleus of atoms.
Only option A correct .

The atomic weight is basically a measurement of the total number of particles in an atom's nucleus. Mass number can be found by rounding off an elements atomic mass to the nearest whole number.
Mass Number $=$ (Number of Protons) $+$ (Number of Neutrons)
$= 11 + 12$
$= 23$

The atomic number is the number of protons in an atom of an element. Atoms are electrically neutral. That means that there must be a balance between the positively charged protons and the negatively charged electrons.

An electron is a tiny particle with a mass of $9.108\times 10^{-28}$ g and a negative charge. All neutral atoms contain electrons. The mass of a proton is $1.6726\times 10^{-24}$ g, or about 1836 times the mass of an electron. The proton carries a positive electrical charge, that is equal in magnitude to the charge of the electron but opposite in sign. Mass of a neutron is $1.675 \times  10^{-24}$ g. It is very close to that of the proton. A neutron carries no charge.

The atomic weight is basically a measurement of the total number of particles in an atom's nucleus. Mass number can be found by rounding off an elements atomic mass to the nearest whole number.
$Mass\ Number = (Number\ of\ protons) + (Number\ of\ neutrons)$
Number of neutrons $= mass\ number- number\ of\ protons$
Atomic mass of silver $= 107.86$
Mass number $= 108$
Number of protons $= 47$
Number of neutrons $= 108 - 47$
$= 61$
$\therefore$ Number of neutrons in a silver $=61$

Positronium is the name given to an atom-like combination formed between a positron and an electron. Electron  and positron are particle and antiparticle.

Mass of one neutron $= 1.675 \times 10^{-27}$ kg

An atom is electrically neutral as it has an equal number of electrons and protons, that is, an equal number of negative and positive charges. 

Mass of an electron $=9.1\times 10^{-28}$g
1 mole $=6.02\times 10^{23}$ electrons
$\therefore$ molar mass of electron $=(9.1\times 10^{-28}) \times (6.02\times 10^{23}) = 5.48\times 10^{-4}$ g/mole

We know that, 1 molecule of water consists of 10 electrons (2 electrons each of two hydrogen atoms and 8 electrons of one oxygen atom).
The number of molecules present in 1.8 g of water.
$18 : g : of : H _2O\xrightarrow[]{contains}6.023\times 10^{23}molecules$
$\Rightarrow1.8 : g : of : H _2O : contains : '! x' : molecules$
$x=\dfrac{1.8\times 6.023\times 10^{23}}{18}$
$=\dfrac{ 6.023\times 10^{23}}{10}=6.023\times 10^{22}molecules$.
$\therefore$ Number of electrons in 1.8 g of water $=6.023\times 10^{22}\times10=6.023\times 10^{23}$

Mass of one electron is $9.108\times 10^{-31} kg$.

Mass of electron $\displaystyle 9.108\times 10^{-31}kg$.
The number of electrons that weigh 1 kg will be $\frac {1}{\displaystyle 9.108\times 10^{-31}}$
The Avagadro number is $\displaystyle 6.023\times 10^{23}$.    
The number of moles of electrons that weigh 1 kg will be
$\frac {1}{\displaystyle 9.108\times 10^{-31} \times \displaystyle 6.023\times 10^{23}}=\displaystyle \frac{1}{9.108\times 6.023}\times 10^{8}$