Answer:
The wavelength for the transition from n = 4 to n = 2 is<u> 486nm</u> and the name name given to the spectroscopic series belongs to <u>The Balmer series.</u>
Explanation
lets calculate -
Rydberg equation- 
where ,
is wavelength , R is Rydberg constant ( 
), 
and 
are the quantum numbers of the energy levels. (where 
)
Now putting the given values in the equation,
Wavelength 
=
= 486nm
<u> Therefore , the wavelength is 486nm and it belongs to The Balmer series.</u>
Answer:
b.) Br and Br
Explanation:
A covalent bond occurs when electrons are shared between two atoms causing them to form a bond.
A "pure" covalent bond refers to a nonpolar covalent bond. In these bonds, the electrons are shared equally between two atoms as a result of the absence of an (or very small) electronegativity difference. The purest covalent bond would therefore be between two atoms of the same electronegativity. Two bromines (Br) have the same electronegativity, thus making it the purest covalent bond.
Polar covalent bonds occur when electrons are shared unequally between two atoms. There is a larger electronegativity difference between the two atoms, but not large enough to classify the bonds as ionic. In this case, a.) and c.) are polar covalent bonds and d.) is an ionic bond.
It is True because in the periodic table of elements, there are seven horizontal rows of elements called periods. The vertical columns of elements are called groups, or families.
The atomic number of an element tells you the number of protons within said element.
LEAD is the element that has this electron configuration
