Answer:
The correct question is:
"Find the energy each gains"
The energy gained by a charged particle accelerated through a potential difference is given by

where
q is the charge of the particle
is the potential difference
For a proton,

And since 
The energy gained by the proton is

For an alpha particle,

Therefore, the energy gained is

Finally, for a singly ionized helium nucleus (a helium nucleus that has lost one electron)

So the energy gained is the same as the proton:

Answer: 4.
Explanation:
Use formula v = d / t, where v = speed, d = distance and t = time.
v = 10 / 2.5
v = 4.
Metal
Explanation:
semiconductors are materials which have a conductivity between conductors (generally metals)
Answer:
Resistivity ρ=1.12 x 10^-4 Ωm
Explanation:
ρ= RA/l, where R is resistance, A is cross sectional area and l is length
A=πr^2
Note Current is given R is proportion to temperature and inversely proportional to Current R=(20+273)/14*10^-2 =2000Ω
⇒ρ=R*πr^2/l all length in metre.
Answer:

It will float.
Explanation:
Hello.
In this case, given the width, length and height, we can compute the volume as follows:

Moreover, since the density is computed via the division of the mass by the volume:

We obtain:

In such a way, since the solid has a lower density than the water, we infer it will float.
Best regards.