Q8.what happened to the mixture?

What causes the lines in the spectrum for elements? a continuous release of energy from the heated element a quantum absorption

solmaris [256]

Answer:a quantum absorption of energy

Explanation:

Bohr’s model explains the spectral lines .While the electron of the atom remains in the ground state, its energy is unchanged. When the atom absorbs one or more quanta of energy, the electron moves from the ground state orbit to an excited state and when the atom relaxes back to a lower energy state, it releases energy that is again equal to the difference in energy of the two orbits.

5 0

2 years ago

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Give the number of protons, neutrons and electrons in 99Tc

miss Akunina [59]

Explanation:

Tc - 99 is technetium 99.

It is a radioactive element that decays spontaneously. It has a half-life of 211,000 years and decays to stable ruthenium.

On the periodic table, it has an atomic number of 43;

Mass number = 99

Atomic number = number of protons = number of electrons in atom

Number of protons in Tc is 43

electron is 43

Mass number = number of protons + number of neutrons

Number of neutrons = mass number - number of protons = 99-43 = 56

learn more:

Atomic number brainly.com/question/2057656

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5 0

3 years ago

When magnesium (mg) metal is placed in hydrochloric acid (hcl), it forms magnesium chloride (mgcl2) and a gas. what gas is forme

Delvig [45]

Magnesium in hydrochloric acid forms H2 (hydrogen) gas according to the balanced chemical equation:
Mg + 2HCl→H2 + MgCl2

6 0

2 years ago

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Which term names the transfer of heat between two objects that are touching

Svetlanka [38]

Answer: Conduction

Explanation:

Conduction means the process by which heat or electricity is directly transmitted through a substance when there is a difference of temperature or of electrical potential between adjoining regions, without movement of the material.

Meaning that its when an object touches another object and heat gets transferred.

5 0

2 years ago

State which of the following set of quantum number would be possible and which would be permissible for an electron in an atom.

raketka [301]

Answer:

The correct option is: e) n=4, l=3, $m_{l}$ = - 2 , $m_{s}$ = - 1/2

Explanation:

The four quantum numbers that describe the electrons in an atom are: The principal: n, azimuthal: l, magnetic: m, and spin: s.

For a given electron, the values of the quantum numbers should be in the given range- principal quantum number: n ≥ 1;

azimuthal quantum number: 0 ≤ l ≤ n − 1;

magnetic quantum number: −l ≤ $m_{l}$ ≤ +l;

spin quantum number: −s ≤ $m_{s}$ ≤ +s

Now, for n= 4,

The value of l: 0 to n − 1 = 0 to 3 = 0, 1, 2, 3

The value of $m_{l}$ for l= 3 : -3 to +3 = -3, -2, -1, 0, +1, +2, +3

The value of $m_{s}$ : -1/2, +1/2

Therefore, the given set of quantum numbers: n=4, l=3, $m_{l}$ = - 2 , $m_{s}$ = - 1/2; are possible and permissible for an electron in an atom.

5 0

2 years ago