Answer:
C-Electrical energy changed into mechanical energy
Explanation:
Energy, according to the law of conservation of energy, is said to neither be created or lost but only interchangeable from one form to another. Energy exists in different forms. The process by which one form of energy changes to another is called TRANSFORMATION of energy.
However, certain household appliances or devices bring about this transformation of energy. For example, in a case where Tony turns a fan on when his room becomes uncomfortably hot. The fan uses an electric source to get powered on, which then facilitates the blades of the fan to move fast in order to bring about a cool atmosphere.
The fan converts ELECTRICAL energy (electric source) into MECHANICAL energy (moving energy).
Water is the BL base if it accepted a proton from NH4.
Can I get brainliest please?
<u>Answer:</u> The equation to calculate the mass of remaining isotope is ![[A]=\frac{20}{10^{-0.217t}}](https://tex.z-dn.net/?f=%5BA%5D%3D%5Cfrac%7B20%7D%7B10%5E%7B-0.217t%7D%7D)
<u>Explanation:</u>
The equation used to calculate rate constant from given half life for first order kinetics:

where,
= half life of the reaction = 
Putting values in above equation, we get:

Rate law expression for first order kinetics is given by the equation:
![k=\frac{2.303}{t}\log\frac{[A_o]}{[A]}](https://tex.z-dn.net/?f=k%3D%5Cfrac%7B2.303%7D%7Bt%7D%5Clog%5Cfrac%7B%5BA_o%5D%7D%7B%5BA%5D%7D)
where,
k = rate constant = 
t = time taken for decay process
= initial amount of the sample = 20 grams
[A] = amount left after decay process = ? grams
Putting values in above equation, we get:
![0.5=\frac{2.303}{t}\log\frac{20}{[A]}](https://tex.z-dn.net/?f=0.5%3D%5Cfrac%7B2.303%7D%7Bt%7D%5Clog%5Cfrac%7B20%7D%7B%5BA%5D%7D)
![[A]=\frac{20}{10^{-0.217t}}](https://tex.z-dn.net/?f=%5BA%5D%3D%5Cfrac%7B20%7D%7B10%5E%7B-0.217t%7D%7D)
Hence, the equation to calculate the mass of remaining isotope is ![[A]=\frac{20}{10^{-0.217t}}](https://tex.z-dn.net/?f=%5BA%5D%3D%5Cfrac%7B20%7D%7B10%5E%7B-0.217t%7D%7D)
Very small pka. can also be - pka.
There are two types of 'quantities' namely: scalar and vector
A 'vector' is a quantity that has both magnitude and direction whereas a 'scalar' has only magnitude.
Magnitude is a measure or the size of the quantity or object.
In the given example of the vector: '75 mph to the north'
Magnitude is the number 75 mph
Direction is north
Ans C)