D is the answer. It is a firm statement.
B)
If it is known that the atomic number is 8, we know that the electrons are also 8. Since the atomic mass (O18) is 18, the neutrons are 18-8=10. Option B is the correct answer.
Hope I helped :)
Answer: 0.1 m/s
Explanation:
Use formula,
v = f * w where, v is speed, f is frequency and w is wavelength.
Now,
v = 2 * 5 * 10 ^ -2 ( Remember to convert all the units to SI units. Here 5 cm becomes 5 * 10 ^ -2 m. )
v = 0.1 m/s.
Pitch is directly related to the frequency of the sound. In this item, we are given that the frequency of the sound is higher compared to those which are audible to the human being's ears. The pitch therefore of the dog's whistle is high.
On the other hand, the frequency and the wavelength of a certain wave are inversely proportional. This means that the high frequency wave will have a short wavelength.
Hence, the answer to this item would have to be "high pitch with a short wavelength"
The answer to this item is the second option.
Answer:
1) The matter absorbs or reflects the light
2) Lens
3) <u><em>Concave</em></u>- curves inwards. Diverges light
b.<u><em>Convex</em></u>- curves outward. Converges light
4) The image is real if the distance of the object from the lens is greater than the focal length and virtual if it is less than the focal length
5) Lens and, for convex lenses, on the distance between the lens and the object.
6) Index of refraction?
Explanation:
I hope this helped you, sorry if anything is wrong
