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.
PH scale is used to determine how acidic , basic or neutral a solution is. It can be calculated using the following equation
pH = -log [H₃O⁺]
hydronium ion concentration has already been given
[H₃O⁺] = 4.91 x 10⁻⁴ M
pH = -log[4.91 x 10⁻⁴ M]
pH = 3.3
the pH of medium is 3.3
The top soil would most likely be thicker in lush tropical area.
Explanation:
The top soil presents just above the earth's surface in the upper position of soil profile. It's thickness is 2 to 3 inches. Tropical area receives highest rainfall and direct sunlight which promotes the growth of lush vegetation that tightly holds the soil.
Dry region is devoid of vegetation. And it is free zone for air passing. With high speed wind top soil blow out from the upper surface and make surface bare. The thickness of soil in tropical area is maximum and pure.
The correct answer should be D. can be real or virtual depending on the object's placement
Depending on the position on the mirror, it can be determined whether the object is real or virtual.
Answer: It is made up of one element