periodic table valence electron definition

#Periodic table valence electron definition series

Which has a negative charge orbits around the nucleus

Protons have a positive charge, 'electrons have a negative charge, 'so they'll be attracted to each other.' Opposite signs, opposite charges attract. And early physicists and chemists said, 'All right, well, if the Would have two neutrons as well so the nucleus might Protons in the nucleus and a typical helium atom Which is made up of the protons and the neutrons isĬoncentrated at the center and so the early modelįor how an atom worked was maybe you have your protonsĪnd neutrons in the center so let's say, we're talkingĪbout a helium atom. Physicist and chemists were facing over a hundred years ago is how are these things configure and they realized that the positive charge is concentrated at the center of the atom. Which have neutral charge or no charge and then you have your electrons And those particles are the protons which have positive charge, you have your neutrons Learned in other videos that the atom is in fact made up of even smaller constituent particles which is pretty amazing because atoms are already So in the sun it isn't really a case of helium combining with hydrogen in a reaction sense, rather they are just in close proximity to each other in a mixture.

#Periodic table valence electron definition series

The main nuclear reaction occurring in the sun are series of nuclear reactions called the proton-proton chain (because it begins with the collision of two hydrogen atoms containing a single proton each) which eventually results in helium atoms.īut once helium is formed, it doesn't really combine with hydrogen afterwards in either chemical or nuclear reactions. Essentially what happens in the sun is that atoms of hydrogen-1 (that is isotopes of hydrogen with a single proton only) collide into each other with such force that they fuse into new atoms. Nuclear reactions are different from chemical reactions in that chemical reactions only involve the electrons of atoms and do not touch nuclei of atoms where we find protons and neutrons while nuclear reactions involve the nuclei of atoms. In the sun we don't really have chemical reactions involving helium, rather nuclear reactions. Helium doesn't really react chemically because its valence shell is filled and it is stable in its natural electron configuration. Reactions where the valence electrons of atoms interact to form new chemicals by breaking and forming chemical bonds. Usually in chemistry we're concerned with chemical reactions. The 2p orbital is closer to the nucleus than the 3s orbital, because it is in the second shell, which is closer to the nucleus than the third shell. In the third shell we again find p and s orbitals. Them comes the third shell even further away from the nucleus. But the 2s is of course further away from the nucleus, because it is in the second shell. In the second shell there are s and p orbitals. So in the first shell there is only one subshell, the s orbital. Now let's have a look at each shell in detail. The smallest, nearest to the nucleus is shell number 1. Imagine shells around the nucleus, that get bigger and bigger. This is also due to the history when they were discovered. We classified the different Orbital into shells and sub shells to distinguish them more easily. An orbital is a space where a specific pair of electrons can be found.