Les ｓ o ｎ 1 The Ｂａ sic Concepts for N ｕｃ lear Phy ｓ ic ｓ１、1 Atoms an ｄNu ｃ le ｉＴｈ e at ｏｍｓ of all e ｌ eme ｎ ts, wh ｉ ch a ｔ ｏｎ e t ｉ me w ｅ re th ｏ ugh ｔ to b ｅth ｅ fu ｎｄ amen ｔａｌ p ａ rticles o ｆｎ at ｕ r ｅ, ｃ onsist ｏ f numb ｅｒ s of t ｈ r ｅ e ｍ ore fund ａ me ｎtal p ａ r ｔｉｃ les-p ｒｏ to ｎ s ， n ｅ utr ｏ ns ａ nd el ｅ ct ｒ o ｎ s 、 T ｈ e ａ rr ａ nge ｍｅ nt of these pａ r ｔ i ｃｌ es w ｉ thin th ｅ at ｏ m, ａ n ｄin partic ｕ lar the number of pr ｏ tons a ｎ d ele ｃｔrons, dete ｒ m ｉ n ｅ t ｈ e ｃｈ emi ｃ a ｌ identi ｔ y of the el ｅｍ e ｎ t 、 T ｈ e atom ｃ o ｎ sists of nucleus ｉ n which all ｔ he ｐ osi ｔ ive ｌ y char ｇｅ d ｐ rotons ａ nd unch ａ rge ｄ ｎ eutrons ａ re close ｌ y g ｒ oupe ｄ toge ｔ her ， and ａｎ umber of nega ｔ ive ｌ y cha ｒ g ｅ d ｅｌｅ c ｔ rons movi ｎ g i ｎorbital ｐ aths around ｔｈ e nu ｃ le ｕ s 、 I ｎ ａ n el ｅ ctricall ｙ ne ｕ tra ｌ or ｕnioniz ｅ d ａ to ｍ th ｅ num ｂｅ r of prot ｏ ns is ｅ qua ｌ t ｏｔ he number of e ｌ ec ｔ rons, ａ nd this number, Z ， is ｔ he atomic numb ｅ r of ａ particular elemen ｔ ａｎ d i ｄ e ｎ tifies ｉ t 、 (This numbe ｒ cor ｒｅ sponds ｔ o ｔ he po ｓ iti ｏ n of t ｈ e ele ｍｅ nt in t ｈ e Period ｉ c Ｔａ bl ｅ、） T ｈ e nuｍ ber o ｆ ne ｕ t ｒ o ｎｓin ｔ he nucl ｅｕｓ is denoted by N, an ｄ t ｈ e s ｕ m o ｆ the nu ｍ ber of neutro ｎ s an ｄ pr ｏ t ｏｎｓ in t ｈ e n ｕ cl ｅｕｓ is call ｅｄ, ｆ or rea ｓ o ｎthat w ｉ l ｌ sho ｒｔ ly be app ａｒ ent, th ｅ mass...
