Answer:
Calcium and barium
Explanation:
Krypton is a noble gas it do not take part in any reaction its physical and chemical property does not resembles to other atoms.
Hydrogen is the reducing gas its physical and chemical property does not resembles to other atoms.
Silicon is a semiconductor its physical and chemical property does not resembles to other atoms.
Calcium and Barium are placed in the same group 2 in the periodic table . Both are alkaline earth metal.
As both element are placed in the same group they have same physical and chemical properties.
Example:
- Electro-negativity of Calcium and barium are approximately same.
- Both have same oxidation states +2, both are strong basic oxide.
- Both are present in nature in solid state.
- Both are s- block element.
Thus, we can say Barium and Calcium have similar properties.
1.472 N
to get weight you multiply an object's mass in kilograms with the acceleration of gravity(9.81m/s) :)
Well, I'll try to write the formula in a way that's not confusing,
but I'm afraid it might be slightly confusing anyway.
When you're working with dB, the basic rule is
A change of 10 dB means either multiplying or dividing by 10 .
Multiply something by 10 ==> it increases by 10 dB.
Divide something by 10 ==> it decreases by 10 dB.
It turns out that another way to write all of this is . . .
An increase of 10 dB ===> multiply the original amount by 10¹
An increase of 20 dB ===> multiply the original amount by 10²
An increase of, say, 7 dB ===> multiply the original amount by 10⁰·⁷
A decrease of 10 dB ===> multiply the original amount by 10⁻¹
A decrease of 30 dB ===> multiply the original amount by 10⁻³
A decrease of, say, 13 dB ===> multiply the original amount by 10⁻¹·³
This question says: The sound increases by 5 dB .
That means the original 'intensity' or 'power' of the sound
is multiplied by
10⁰·⁵ = √10 = about 3.162 (rounded) .
From the choices listed, the closest one is (c).
Kilogram(kg)
It's not the SI unit of mass in the metric system however.
Answer:3W
If it takes an amount of work W to move two q point charges from infinity to a distance d apart from each other, then how much work should it take to move three q point charges from infinity to a distance d apart from each other?
A) 2W
B) 3W
C) 4W
D) 6W
Explanation: calculating work done,W, in moving two positive q point charges from infinity to a valued distance d from each other is
W = k(+q)(+q)/ d
k is couloumb's constant
work done in moving 3 equal positive charges from infinity to a finite distance is given by
W₂=W₄=W₆=k(+q)(+q)/ d
Total work done, W' =k(+q)(+q)/ d + k(+q)(+q)/ d + k(+q)(+q)/ d
= W + W + W = 3W
