Explanation:
1. Democritus proposes the existence of atoms
2. Dalton's atomic theory
3. J. J. Thomson discovers the electron
4. Rutherford's gold foil experiment
5. Bohr model
6. Schrödinger's Wave Mechanics model of the atom
The first idea about matter containing atoms dates back to Greek philosophers. One of them was Democritus .
In 1808 Dalton put forward his atomic theory
In 1897 J.J Thomson discovered cathode rays using his gas discharge tube experiment.
In 1911, Ernest Rutherford proposed the nuclear model of the atom using experiments on the gold foil.
Neils Bohr in 1913 suggested his own atomic model
Erwin Schrodinger formulated the wave equation of electrons
Learn more;
Dalton atomic theory brainly.com/question/1979129
Rutherford gold foil experiment brainly.com/question/1859083
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Answer:
145.8g
Explanation:
Given parameters:
Number of moles of magnesium hydroxide = 2.5mol
Unknown:
Mass of Mg(OH)₂ = ?
Solution:
To solve this problem we use the expression below;
Mass of Mg(OH)₂ = number of moles x molar mass
Molar mass of Mg(OH)₂ = 24.3 + 2(16 + 1) = 58.3g/mol
Mass of Mg(OH)₂ = 2.5 x 58.3 = 145.8g
Answer: 4
Explanation:
Principle Quantum Numbers: This quantum number describes the size of the orbital. It is represented by n.
Azimuthal Quantum Number: This quantum number describes the shape of the orbital. It is represented as 'l'. The value of l ranges from 0 to (n-1). For l = 0,1,2,3... the orbitals are s, p, d, f...
Magnetic Quantum Number: This quantum number describes the orientation of the orbitals. It is represented as
. The value of this quantum number ranges from
. When l = 2, the value of
will be -2, -1, 0, +1, +2.
Given : a f subshell, thus l = 3 , Thus the subshells present would be 3, 2, 1, 0 and thus n will have a value of 4.
Also electrons give are 32.
The formula for number of electrons is
.


Thus principal quantum no will be n= 4.
Answer:
causes a substance to change from a liquid to a solid.
Explanation:
make or become hot or warm is heating.
cooling is to become colder or cool down from a higher temp.