Answer:
d Rubidium
Explanation:
The atomic radius of an atom is the distance from the center of the nucleus to its outermost electron.
The atomic radius of elements varies in the periodic table, it increases as you go down in a group and decreases along the period from left to right.
All the elements listed: Hydrogen, Sodium, Lithium and Rubidium belong to the same group in the periodic table (group 1), Since atomic radius increases from top to bottom in a group, Rubidium has the largest atomic radius.
Answer:
B
convex: for long sightedness
Or
A
concave: for short sightedness
Explanation:
here is the answer to your question
Answer:
The absorption and strength of the H-beta lines change with the temperature of the stellar surface, and because of this, one can find the temperature of the star from their absorption lines and strength. To better comprehend, let us look into the concept of the atom's atomic structure.
Atoms possess distinct energy levels and these levels of energy are constant, that is, the temperature has no influence on it. However, temperature possesses an influence on the electron numbers found within these levels of energy. Therefore, to generate an absorption line of hydrogen in the electromagnetic spectrum's visible band, the electrons are required to be present in the second energy level, that is when it captivates a photon.
Therefore, after captivating the photons the electrons jump from level 2 to level 4, which shows that there is an increase in the stellar surface temperature and at the same time one can witness a decline in the strength of the H-beta lines. In case, if the temperature of the surface increases too much, then one will witness no attachment of electron with the hydrogen atom and thus no H lines, and if the temperature of the surface becomes too low, then the electrons will stay in the ground state and no formation of H lines will take place in that condition too.
Hence, to generate a very robust H line, after captivating photons the majority of the electrons are required to stay in the second energy level.
Answer:
No. of protons = 34
Explanation:
First we need to calculate the number of electrons in one mole of the the element:
No. of electrons per mole = Total Mass of Electrons/Mass of 1 Electron
No. of electrons per mole = (18.65 x 10⁻³ g)/(9.109 x 10⁻²⁸ g)
No. of electrons per mole = 2.04 x 10²⁵ electrons/mol
Now, we calculate the no. of electrons in 1 atom:
No. of electrons per atom = No. of Electrons per mole/No. of atoms per mole
No. of electrons per atom = (2.04 x 10²⁵ electrons/mol)/(6.022 x 10²³ atoms/mol)
No. of electrons per atom = 34 electrons/atom
Since, the no. of protons in a pure element are equal to the number of electrons. Therefore,
<u>No. of protons = 34</u>
