Answer: An element os made up of one kind of atom.
Explanation: Dalton's concept states that all atoms of an element is identical.
Answer:
Atom is the smallest particle of matter.
Elements are made up of same atoms.
Atom consist of electron, proton and neutron.
Explanation:
Atom was first discovered by John Dalton.
word "Atom" came from Greek word, that means something that could not split. he explained that atom is indivisible particle.
In the end of 18th century J.J. Thomson put forward a new concept of atom. he said that atom have negative charged particles called electrons but overall atom is neutral.
In 1909 Rutherford with his students discovered positive charged particles and nucleus and said that it is in the center of atom.
He explain a model of atom and said that electrons revolve around a hard core in the center called nucleus.
In 1913 Niels Bohr explains the atomic spectra and put forward the concept of shells and sub-shells.
So overall Structure of an Atom is
- consist of Neutrons in nucleus
- +ve charged protons in nucleus
- A -vely charged electrons revolving around the nucleus
- the electron revolve in shells i.e. K, L, M, and N
- Each shell divide in sub-Shell such as s, p,d and f.
Atom has a specific atomic mass and atomic number
Atomic number = number of protons or electron
Atomic mass = number of protons + number of neutrons in nucleus.
Answer:
Rutherford's theory laid the foundation upon which Bohr's model is founded. Rutherford established the fact that at the center of the atom, there is a nucleus whose radius is smaller than the radius of the atom. This nucleus is positively charged and most of the mass of the atom is concentrated there. Electrons move round this nucleus in orbits.
The experimental evidences of the Bohr's model shows that Rutherford's model was fundamentally correct. However, Bohr's model introduced the idea of quantization of the energy of electrons in an atom. The model went further to explain the spectra lines of the hydrogen atom.
Explanation: