Which of the following observations indicates that an atom has neutrons?

A. Some uncharged particles are scattered by a beryllium atom when it hits a gold foil.
B. Some uncharged particles bounce back from a gold foil when it is bombarded with alpha particles.
C. A radiation with neutral particles is emitted when alpha particles strike beryllium atoms.
D. A radiation which attracts electrons is produced when a beryllium atom is bombarded with alpha particles.

the ideal gas law equation is as follows

pv = nrt

where p - pressure

v - volume

n - number of moles

r - universal gas constant

t - temperature

so if the pressure, volume and temperature are already known

we are left with n and r

since r is the universal gas constant that has a known fixed value then r too is known

so we are left with 'n'

once we know temperature volume and pressure

we can find the number of moles of gas present using the ideal gas law equation

this is not my own answer, this is an answer for the same question by the user blahblahmali. i do not claim ownership of this account.

hey there!

mass = 6.75 g

volume =   9 cm³

therefore:

d = mass / volume

d   = 6.75 / 9

d = 0.7 g/cm³

answer b