What was different about the atomic theory proposed by niels bohr?

the atom's mass was limited to the center of the atom
the addition of electrons to orbit the nucleus
electrons energy levels related to their orbits
a positively charged nucleus in the center of the atom

the number of protons in the nucleus of a given element. has slight luster and conducts electricity at high temperatures like metal.but like a nonmetal,boron is brittle and does not conduct electricity well at low temperatures. in graphite, carbon is a soft,brittle solid.it is reflective,ductile,or malleable.

i dont know the answe

colorless gas, exhibiting a blue glow when placed in an electric field

b) solid

its a type of rock