Answer:
Krypton
Explanation:
When Selenium forms an ion, it is trying to become krypton which is a noble gas.
Selenium belongs to the oxygen group on the periodic table. In this group, the atoms prefers to gain two electrons to complete their octet. When selenium gains two electrons, its octet is complete.
This will make the atom resemble krypton on the periodic table of elements.
This structure which is an octet confers a special stability on the element.
Answer:
boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te), polonium (Po) and astatine (At)
Explanation:
metalloids are elements that are in between the metals and nonmetals. they are in between because they have properties of both metals and nonmetals.
you can search "metalloids on the periodic table" and go to images to see what i mean :)
Hard question !! Is this math .. if not then oh okay cause I’m bad at math but good at everything else so let me think about it !
The atoms of hydrogen that are present in 7.63 g of ammonia(NH3)
find the moles of NH3 =mass/molar mass
7.63 g/ 17 g/mol = 0.449 moles
since there is 3 atoms of H in NH3 the moles of H = 0.449 x 3 = 1.347 moles
by use of 1 mole = 6.02 x10^23 atoms
what about 1.347 moles
= 1.347 moles/1 moles x 6.02 x10^23 atoms = 8.11 x10^23 atoms of Hydrogen
