Answer: Bohr postulated that electronic energy levels are quantized. Secondly, a photon of light of a particular frequency is emitted when electrons move from a higher to a lower energy levels.
Explanation:
The Bohr model of the atom is the immediate predecessor of the wave mechanical model of the atom. The wave mechanical model refined the Bohr's model by treating the electron as a wave having a wave function psi. The wave function describes the identity of the electron. From Heisenberg uncertainty principle, the position of a particle cannot be accurately and precisely measured. Hence the wave mechanical model added that electrons are not localized in orbits according to Bohr's model but the integral of psi squared dx gives the probability of finding the electron within a given space.
Answer:
Physical and psychological dependence is high, and withdrawal symptoms include watery eyes, runny nose, loss of appetite, irritability, tremors, panic, abdominal cramps and diarrhea, nausea, chills, and sweating. Use of contaminated syringes/needles to inject drugs may result in serious blood borne infections such as HIV-AIDS and hepatitis.
<u>Answer:</u>
Nitrogen gas be a mineral only, if it is in organic forms.
<u>Explanation:</u>
Most of the forms of organic nitrogen is not be taken by plants, with the exception in the form of small organic molecules. Also plants can promptly take the nitrogen when it is in other forms like ammonia and nitrate.
The microorganisms in the soil converts the organic forms of nitrogen to mineral form when they decompose organic matters and also fresh plant residues. This type of process is called mineralisation.
Answer:
8.13 ×10²³ atoms
Explanation:
Given data:
Mass of magnesium = 32.45 g
Number of atoms = ?
Solution:
Number of moles of Mg:
Number of moles = mass/molar mass
Number of moles = 32.45 g/ 24 g/mol
Number of moles = 1.35 mol
Number of atoms:
1 mole contain 6.022×10²³ atoms
1.35 mol × 6.022×10²³ atoms/ 1mol
8.13 ×10²³ atoms
