The net charge on a neutral atom of an element will be _______.
Zero
An atom is the basic building block of matter. It is made up of even smaller particles called subatomic particles.
Atom Structure and Charges
Atoms contain three main types of subatomic particles:
- Protons: Found in the nucleus, protons have a positive electrical charge.
- Neutrons: Also found in the nucleus, neutrons have no electrical charge (they are neutral).
- Electrons: These particles orbit the nucleus and have a negative electrical charge.
The positive charge of a proton is equal in magnitude but opposite in sign to the negative charge of an electron. Neutrons, having no charge, do not contribute to the overall electrical charge of the atom.
Balancing Charges in a Neutral Atom
An atom is described as 'neutral' when its overall electrical charge is zero. This happens when the total positive charge from the protons in the nucleus is exactly balanced by the total negative charge from the electrons orbiting the nucleus.
For an atom to be neutral, the number of protons must be equal to the number of electrons.
Let's consider an example:
| Particle | Number in a Neutral Atom | Charge per Particle | Total Charge Contribution |
|---|---|---|---|
| Protons | \(n_p\) | +\(e\) | \(n_p \times (+e)\) |
| Electrons | \(n_e\) | -\(e\) | \(n_e \times (-e)\) |
| Neutrons | \(n_{neutron}\) | 0 | \(n_{neutron} \times 0 = 0\) |
In a neutral atom, \(n_p = n_e\). Let's call this number \(N\).
The total positive charge is \(N \times (+e) = +Ne\).
The total negative charge is \(N \times (-e) = -Ne\).
The total charge from neutrons is 0.
The net charge on the atom is the sum of the total positive charge, total negative charge, and the charge from neutrons:
Net Charge = Total positive charge + Total negative charge + Total charge from neutrons
Net Charge = \((+Ne) + (-Ne) + 0\)
Net Charge = \(+Ne - Ne\)
Net Charge = \(0\)
Therefore, a neutral atom has a net charge of zero because the number of positively charged protons is equal to the number of negatively charged electrons, causing their charges to cancel each other out.
Important Questions from Atoms
The ratio of radii of two nuclei having atomic mass numbers 27 and 8 respectively, will be:
Whose experiment showed that atoms have discrete energy levels ?
The ratio of the volume of an atom to the volume of the nucleus is (in terms of order of magnitude):
If $M$ is the mass of water that rises in a capillary tube of radius $r$, then what would be the total mass of water that rises if a capillary tube of radius $r$ and another capillary tube of radius $2r$ are simultaneously placed in water, assuming identical liquid and material properties?
A $Be^{3+}$ ion, initially in its second excited state, absorbs a photon of wavelength $601.6\text{ A}$. The radius of the ion in the resulting excited state in terms of Bohr radius $a_0$ will be (Take $hc = 12500\text{ eV-A}$)
