Answer:
The correct answer is periods. See the explanation below, please.
Explanation:
The horizontal lines in the periodic table are called periods (ranging from 1 to 7) and vertical lines (ranging from 1 to 18).
The period that an element belongs to coincides with the last electronic layer of the element (that compound in period 3 will have 2 electronic layers).
Answer:
See explanation
Explanation:
If the energy of the ground state E1 is known, then we need to measure the difference in energy between the energy levels E5 .and E1. We can obtain this by measuring the frequency or wavelength of a photon that is emitted when an electron moves from energy level E5 to E1.
From Bohr's model;
ΔE = E5 - E1
Hence;
E5 = ΔE + E1
If you look it up it will give you plenty of information. This is what I found:
The valence electrons of metals move freely in this way because metals have relatively low electronegativity, or attraction to electrons. The positive metal ions form a lattice-like structure held together by all the metallic bonds. ... When nonmetals bond together, the atoms share valence electrons and do not become ions
https://www.ck12.org/c/physical-science/metallic-bond/lesson/Metallic-Bonding-MS-PS/
from an external source of power
Explanation:
The energy needed for nuclear fusion comes from an external source of power.
Nuclear fusion is the combination of small sized atomic nuclei to form larger ones.
The reaction releases a huge amount of energy but also requires a large activation energy to start up.
- The energy input require to drive two nuclei into fusion comes from an external source.
- Nuclear fusion has a high activation energy which serves as the energy barrier for this reaction to take place.
- The energy comes from the surrounding and once initiated, spontaneous chain reactions are set up.
learn more:
Nuclear reactions brainly.com/question/10094982
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