60 quad
118
There is not 400th element. So far we only have up to element 118: ununoctium
It takes about 0.89 ms
Platinum is a metal element. atomic number of it is 78.
Noble Gas
118
118
it cost a new laptop which is 118
$78- $118
It cost $98.95
299
There are 117 elements in the periodic table. Elements 1-116 and element 118. IMPROVED ANSWER --------------------------------------------------------------------------------------- 118, but element 117 is so unstable they do not officially count it as being an element on the periodic table yet.
There are 118 neutrons in the element gold.
118
Who told you that chromium had 118 electrons - there are only 24. Check it out with Wikipedia. There you find the element that really has 118 electrons. Happy hunting. (PS - Hint - there is a very close correlation between the number of electrons and the atomic number of the element.)
Element 118 is a noble gas, which means it would be largely unreactive. Only a few atoms of this gas have been synthesized.
There is not 400th element. So far we only have up to element 118: ununoctium