Middle school? lol but, the third one.
The answer is A and B
Explanation: the nucleus was viewed as composed of combinations of protons and electrons, the two elementary particles known at the time, but that model presented several experimental and theoretical contradictions.
AND
Protons and neutrons have approximately the same mass, about 1.67 × 10-24 grams.
<span>Magnetic field lines form circles that go around the wire.</span>
Answer:
Alpha particles carry a positive charge, beta particles carry a negative charge, and gamma rays are neutral. An alpha particle is made up of two protons and two neutrons bound together. Beta particles are high energy electrons. Gamma rays are waves of electromagnetic energy, or photons
Density is mass divides by volume, so
89.6g / 10cm^3 =8.96g /cm^3
*cm^3 is a standard unit of volume*
