2.1 kg of sodium bicarbonate is equal to the 2.1 x 10¹² ng of sample. Option D is correct.
Mass is the quantity of the substance in the body or object. The SI unit of mass is Kilogram.
There are other units of measure,
- Milligram: 1 g is equal to the

- Micro-gram: 1 g is equal to

- Nano-gram: 1 g is is equal to
First convert kg to gram,
Since, 1 Kg = 1000 g
2.1 kg = grams of sample
So,
Do the cross multiplication,

Now, convert 2100 g to nano-grams
Since, 1 g = 1 x 10⁹ ng
2100 g = ng of sample
So,
Do the cross multiplication,

Therefore, 2.1 kg of sodium bicarbonate is equal to the 2.1 x 10¹² ng of sample.
To know more about Mass units,
brainly.com/question/489186
Answer:
a) increase
Explanation:
The frequency of sound produced due to vibration of a string is governed by the following formula
n = 1/2L√T/m ;
L is length of the string in vibration, T is tension in the string and m is mass of string per unit length.
So frequency is inversely proportional to length of the string. Hence shortning of length of string increases the frequency of vibration.
Answer:
0.9 N, east
Explanation:
charge, q = 1 mC = 0.001 C
Electric filed, E = 900 N/C due east
Force, F = q E
F = 0.001 x 900
F = 0.9 N
The direction of force is same as the direction of electric field as the charge is positive in nature. So, the direction of force is also east.
Answer: The accurate statement which describes the transmission of sound through various medium is D.
Explanation:
Sound is longitudinal wave in which the vibration of particles travels parallel to the propagation of the motion of the wave. It requires a medium to travel. It consists of compression and rarefaction.
Sound insulator prevents the sound to travel for example plastic, wood etc. Sound travels faster in solid medium than in liquid medium. Sound travels faster in liquid than in gas. Less elastic material absorbs sound for example paper in compare to inelastic material.
Therefore, the accurate statement which describes the transmission of sound through various medium is "Sound insulators prevent sound from being transmitted better than elastic solids.
Radio waves have the lowest radiant energy, hope this helps :]