Answer:
C
Explanation:
For electromagnetic waves frequency X wavelength = speed of light
f * 2.2 x 10^-11 = 3 x 10^8 m/s
f = 3 x 10^8 / 2.2 x 10^-11
= 1.36 x 10 ^19
= 1.4 x 10^19 with two significant digits
Answer:
a) KOH
Explanation:
In the given balanced reaction
2K + 2H2O → 2KOH + H2
In the compound KOH,
The elements are K,O, and H and in the compound, there is one mole each of K , O ,and H.
So the element ratio here is 1 : 1 : 1.
Answer:
It is longer than a solar eclipse
Following the key in the diagram (see the attached image), the only particle diagram that represents a mixture of three substances is diagram 2.
To simplify it, let us replace the key in the diagram as follows;
- atom of one element = A
- atom of different element = B
Diagram 1 consists of only AA and AB
Diagram 2 consists of AA, BB, and AB.
Diagram 3 consists of AA and ABA
Diagram 4 consists of AA and BAB
Thus, only diagram 2 has a mixture of 3 substances.
More on mixtures can be found here: brainly.com/question/6594631