Answer: The electronic configuration of potassium atom in excited state is 
Explanation:
There are 2 states classified under energy levels:
1. Ground state: This is the lower energy state which is termed as stable state.
2. Excited state: This is the upper energy state and is termed as the unstable state. All the electrons which are present in this state always come back to the ground state.
Ground state electronic configuration of potassium (Z = 19) : 
As, only 1 electron can freely move to upper state. Hence, the excited state electronic configuration of potassium will be: 
Answer:
the sample undergo
disintegrations per second.
Explanation:
Given:
The amount of sulphur purchased is 0.671 μCi
To find:
disintegrations per second = ?
Solution:
Some of the conversions are

1 rad = 0.01 Gy
1Gy = 1 j/kg tissue
1 rem = 0.01 Sv
1Sv = 1 j/Kg
Using these conversions,
The decay rate of this sample is calculated as

=
disintegrations per second
There is 3.58 He in the balloon.
Acids are chemicals with a pH less than 7 that can donate a proton or H+ ion in a reaction. Bases have a pH greater than 7 and can accept a proton or produce an OH- ion in a reaction. If you mix equal amounts of a strong acid and a strong base, the two chemicals essentially cancel each other out and produce a salt and water. Mixing equal amounts of a strong acid with a strong base also produces a neutral pH (pH = 7) solution. This is called a neauturization and looks like
HA + BOH → BA + H2O + heat
Ka x Kb = Kw Kw = 1 x 10⁻¹⁴
(1.3 x 10⁻⁷) x Kb = 1 x 10⁻¹⁴
Kb = ( 1 x 10⁻¹⁴ ) / ( 1.3 x 10⁻⁷)
Kb = 7.7 x 10⁻⁸
Answer D
hope this helps!