Iodine..............................
Hey there!
27 tells us the sum of protons and neutrons is 27.
Al tells us we have 13 protons.
3+ tells us that there are 3 less electrons than protons.
13 + n = 27
neutrons = 14
13 - 3 = 10 electrons
27Al3+ has 13 protons, 14 neutrons, and 10 electrons.
Hope this helps!
Answer:
Explanation:
The period law state that when elements are listed in order of their atomic numbers, the elements fall into recurring groups, so that there is a recurrence of similar properties at regular intervals.
Na and K in the periodic table fall into the same group, this is because they both have one electrons in their outermost shell.
Na 11 -1s2 2s2 2p6 3s1
K 19 - 1s2 2s2 2p6 3s2 3p6 4s1
They share similar chemical and physical properties. Na and K are very reactive metals, they can loose/donate their outermost electron to non metals in other to attain stable octet state.
The form ionic compound when they react with non metals.
Answer:
Around 450 B.C.
Explanation:
The idea was forgotten until the 1800 when John Dalton re-introduced the atom.
The vapors of some chemicals used in the chemistry laboratory, especially isocyanates, can react and bond the contact lens to the eye.
(FYI - the family of isocyanates include Superglue..I wouldn't want to have been the person who discovered this unfortunate reaction!)
