Answer:
The atomic mass on the periodic table is a decimal number because it is an average of the different isotopes of an element.
P.S.
An isotope is each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei, and differ in relative atomic mass but not in chemical properties; in particular, a radioactive form of an element.
Answer:
here are some examples of physical change!!!
Explanation:
-An ice cube melting into water in your drink.
-Freezing water to make ice cubes.
-Boiling water evaporating.
-Hot shower water turning to steam.
-Steam from the shower condensing on a mirror.
Answer:
A type of an atom which has a different number of neutrons but the same atomic number, therefore making it the same element. This atom would still have the same properties as well. (Ex: Vanadium-51 is an isotope of Vanadium that has 51 neutrons but still has 23 protons, as its atomic number is 23.)
Answer:vv

Explanation:
The expression for the deBroglie wavelength is:
Where,
is the deBroglie wavelength
h is Plank's constant having value
m is the mass of =
v is the speed.
Wavelength = 5400 Å = 
Applying in the equation as:-


Answer:
D.) The nuclear model describes the atom as a dense, positive nucleus surrounded by a cloud of negative electrons.