Answer:
D. Metallic atoms have valence shells that are mostly empty, which
means these atoms are more likely to give up electrons and allow
them to move freely.
Explanation:
Metals usually contain very few electrons in their valence shells hence they easily give up these few valence electrons to yield metal cations.
In the metallic bond, metal cations are held together by electrostatic attraction between the metal ions and a sea of mobile electrons.
Since metals give up their electrons easily, it is very easy for them to participate in metallic bonding. They give up their electrons easily because their valence shells are mostly empty, metal valence shells usually contain only a few electrons.
Answer:
The speed of this light and wavelength in a liquid are
and 442 nm.
Explanation:
Given that,
Wavelength = 650 nm
Index refraction = 1.47
(a). We need to calculate the speed
Using formula of speed

Where, n = refraction index
c = speed of light in vacuum
v = speed of light in medium
Put the value into the formula



(b). We need to calculate the wavelength
Using formula of wavelength


Where,
= wavelength in vacuum
= wavelength in medium
Put the value into the formula


Hence, The speed of this light and wavelength in a liquid are
and 442 nm.
Answer:
A force pump can be used to raise water by a height of more than 10m, the maximum height allowed by atmospheric pressure using a common lift pump.
In a force pump, the upstroke of the piston draws water, through an inlet valve, into the cylinder. On the downstroke, the water is discharged, through an outlet valve, into the outlet pipe.
In a string of length L, the wavelength of the n-th harmonic of the standing wave produced in the string is given by:

The length of the string in this problem is L=3.5 m, therefore the wavelength of the 1st harmonic of the standing wave is:

The wavelength of the 2nd harmonic is:

The wavelength of the 4th harmonic is:

It is not possible to find any integer n such that
, therefore the correct options are A, B and D.