Answer:
atom -
the smallest particle of a chemical element that can exist.
atomic mass-
the quantity of matter contained in an atom of an element
atomic weight -
ratio of the average mass of a chemical element's atoms to some standard
protons-
stable subatomic particle that has a positive charge equal in magnitude to a unit of electron charge and a rest mass of 1.67262 × 10−27 kg
electrons-
a stable subatomic particle with a charge of negative electricity, found in all atoms and acting as the primary carrier of electricity in solids
neutrons-
a subatomic particle of about the same mass as a proton but without an electric charge, present in all atomic nuclei except those of ordinary hydrogen.
energy levels-
one of the stable states of constant energy that may be assumed by a physical system
[used especially of the quantum states of electrons in atoms and of nuclei. — called also energy state.]
Covalent bonds
the interatomic linkage that results from the sharing of an electron pair between two atoms.
ionic bonds
type of linkage formed from the electrostatic attraction between oppositely charged ions in a chemical compound.
Valence electrons
a single electron or one of two or more electrons in the outer shell of an atom that is responsible for the chemical properties of the atom.
Lewis Dot Diagram
A way of representing atoms or molecules by showing electrons as dots surrounding the element symbol. One bond is represented as two electrons.
Inertia: tendency of an object to resist changes in its velocity. An object at rest has zero velocity - and (in the absence of an unbalanced force) will remain with a zero velocity. Such an object will not change its state of motion (i.e., velocity) unless acted upon by an unbalanced force.
An excited atom can return to its ground state by absorbing electromagnetic radiation is false about the electromagnetic radiation.
Option B
<u>Explanation</u>:
In the scope of modern quantum theory, the term Electromagnetic radiation is identified as the movement of photons through space. Almost all the sources of energy that we utilize today such as coal, oil, etc are a product of electromagnetic radiation which was absorbed from the sun millions of years ago.
Various properties of electromagnetic radiations are a directly proportional relationship between the energy and the frequency, Inverse proportionality between frequency and the wavelength, etc. Hence, we can conclude that an "excited atom" can never return to its ground state by assimilating electromagnetic radiation and the 2nd statement is false.
Answer:

Explanation:
We are given that
d=0.23 mm=

Screen is placed from the slits at distance ,L=4.75 m
The bright interference fringes on the screen are separated by 1.56 cm.

1 m=100 cm
We have to find the wavelength of laser light.
We know that

Substitute the values



Answer: The 5 uses of mechanical energy are: 1) Hammering a nail
2) Using Dart gun 3) Moon 4) Hydropower plant 5) Sharping a pencil.