2006-12-05 10:50:18 · 5 answers · asked by Anonymous in Science & Mathematics ➔ Physics
always 3 p
isotope of Li-7 will have 4 n
a neutral Li atom will have 3 e
2006-12-05 10:53:10 · answer #1 · answered by Math-Chem-Physics Teacher 3 · 0⤊ 0⤋
Lithium is the third element of the periodic table. It has a mass number of 3, hence it has 3 protons. The atomic weight of Lithium is given as 6.941 Now atomic weight is quite tricky. Though it should indicate a value for the total mass (in atomic mass units) inside a nuclues, i.e. the total number of protons plus neutrons, it is in fact a measure of the element's mass when compared to carbon-12. So, the numeber 6.941 is in fact a ratio. You may ask, why is it not a whole number? The fact is that Lithium occurs more naturally (92.41%) as a stable isotope: Li-7, which has 3 protons and 4 neutrons. The remaining 7.59% is found naturally as Li-6, with 3 protons and 3 neutrons. However, one can say that no. of neutrons = mass number - atomic number. If the atom is uncharged - though the word atom stricly implies that it is uncharged; charged atoms are called ions - the number of electrons would be equal to the number of protons. In Lithium's case this is 3.
2016-05-22 22:24:45 · answer #2 · answered by Anonymous · 0⤊ 0⤋
Li is element 3 on the periodic table. Thus it has 3 protons and 3 electrons. The most abundant isotope is lithium-7. which means it must have 4 neutrons... however it can have more or less depending on what isotope you have.
2006-12-05 10:54:59 · answer #3 · answered by Jud R 3 · 0⤊ 0⤋
3 protons, 3 electrons
Different isotopes can have from 1 to 9 neutrons
2006-12-05 10:56:00 · answer #4 · answered by Anonymous · 0⤊ 0⤋
Look it up in the periodic table of elements. Nowadays I'm sure its on line.
2006-12-05 10:54:05 · answer #5 · answered by Shira D 2 · 0⤊ 0⤋