Answer:
Discovery of neutron
Explanation:
Until 1932, the atom was believed to be composed of a positively charged nucleus surrounded by negatively charged electrons, after successful discovery of electron by J.J. Thompson and proton by Ernest Rutherford.
In 1932, James Chadwick bombarded beryllium atoms with alpha particles.
As Chadwick had previously seen in experiment conducted by Frédéric and Irène Joliot-Curie, they had bombarded a sample of beryllium with alpha radiation.
Chadwick repeated the experiment and observed an unknown radiation, this showed no deflection what-so-ever.
He repeated this experiment by bombarding other materials, like helium, nitrogen and lithium,
Finally, Chadwick found that this radiation was composed of particles with a neutral electrical charge and had approximate mass of a proton.
This particle was then known as the neutron.
Answer:
See Explanation
Explanation:
In electrophilic aromatic substitution, the benzene ring undergoes substitution when it is reacted with suitable electrophiles.
The products of electrophilic aromatic substitution depends on the substituents already present on the benzene ring. Some substituents activate the ring towards electrophilic substitution and direct the incoming electrophile to the ortho and para positions on the ring while some substituents deactivate the benzene ring towards electrophilic substitution and direct the incoming electrophlle to the meta position on the ring.
The amide substituent is moderately activating and is an ortho, para director hence the products shown in the mage attached to this answer.
The equation for density id D=M/V, which is density is equal to mass over volume. The mass (46.8 g) divided by the volume (6 cm^3), is the density. I calculated it to be 7.8 g/cm^3
First statement
Fifth statement
Sixth statement