Answer:
it was Millikan. He conducted the oil drop experiment. Thomson determined the electon charge not the quantity. Rutherford used the gold foil experiment to find positive charge and that most of the atom is empty space. Dalton proposed that matter was made of small particles called atoms but that was a concept already proposed by ancient greeks. Dalton also proposed the atomic theory.
Answer: -
²²³Ra is the daughter nuclide produced when ²²⁷Th undergoes alpha decay
Explanation: -
When alpha decay occurs, the mass number of the parent decreases by 4 and the atomic number decreases by 2.
Mass number of ²²⁷Th =227
Atomic number of ²²⁷Th = 90
Mass number of daughter = 227 - 4 = 223
Atomic number of daughter = 90 - 2 = 88
88 is the atomic number of Ra Radium.
Thus the daughter is ²²³Ra
Answer:
1.5 moles
Explanation:
The equation of the reaction is given as:
2 MnO2 + 4 KOH + O2 --> 2KMnO 4 + 2KOH + H2
From the equation,
2 moles of MnO2 produces 2 moles of KMnO4
x moles of MnO2 would produce 1.5 moles of KMnO4
2 = 2
x = 1.5
Solving for x;
x = 1.5 * 2 / 2
x = 1.5 moles
Answer: The net change in the atoms is the conversion of a neutron to a proton, turning Carbon (6 protons) into Nitrogen (7 protons).
Explanation:
Carbon-14, generated from the atmosphere, has 6 protons and 8 neutrons. That's where the 14 comes from, called the mass number, is the sum of protons and neutrons (6+8=14).
Carbon-14 is radioactive and decays by beta decay. That means one of its neutrons spontaneously turns into a proton, an electron, and a neutrino, according to:
After that, the atom has 7 protons and 7 neutrons, maintaining its mass number but changing its atomic number from 6 to 7, turning into Nitrogen.
Answer:
The number of neutron in the Aluminium Isotope is :
B. 14
Explanation:
Isotopes : These are the atoms which have same atomic number but have different mass number.
<u>This image shows the average atomic mass of Al element because it is in decimals</u>.
Atomic mass = 26.98154
(Note : mass number of single isotope can never be in decimals)
It is the average of mass of different isotopes of Al
Major Isotopes of are :
- ......atomic mass = 26
- .......atomic mass = 27
mass of Al given in image(26.98) is nearly equal to mass of 2nd isotope(27)
mass of
Now calculate the neutron in
Number of neutron = mass number - atomic number
= 27 - 13
Number of neutron = 14
(Atomic mass is same as mass number)