Structure of an atom

What are JJ Thomson’s conclusion on an atom

An atom consists of a positively charged sphere and all electrons are embedded in it.

The positive and negative charges of an atom are equal so the atom as a whole is electrically neutral

why did Rutherford take gold foil for his experiment

Rutherford used gold foil because it is thin and malleable, allowing alpha particles to pass through with minimal scattering, and it was around 1000 atoms thick

what are the observations for Rutherford’s experiment

Rutherford's experiment observed that most alpha particles passed straight through the gold foil, while a small fraction were deflected at small angles, and some of them rebound back

what are the conclusions for Rutherford’s experiment?

Most of the space inside an atom is empty, because most of the alpha particles passed through the gold foil without getting deflected

very few particles were deflected from their path indicating that the positive charge of an atom acquires very little space

all the positive charge and the mass of gold atom were concentrated in a small volume of an atom

Drawback of Rutherford’s model of atom

Any particle in a circular orbit would go under acceleration and during acceleration the particles would radiate energy and eventually fall into the nucleus, leading to instability.

what are bohr’s postulates?

Only certain special orbits known as discrete orbits of electrons are allowed inside an atom

while revolving in discrete orbit, electrons wont radiate energy.

What are valence electrons?

The electrons present in the outermost shell of an atom are known as valence electrons

The max number of electron in outermost shell is?

8

What is an atomic number? By which letter is it denoted?

the number of protons present in an atom, it is denoted by Z

Mass of an atom is practically due to protons and neutrons, what is the other name for them?

neucleons