the neutron and the electron cloud
O the neutron and the proton cloud
O the nucleus and the electron cloud
Answer:
the nucleus and electron cloud is the correct option
Answer:
3.16 × 10−8
Explanation:
The fluoride ion (F-) is smaller in size than the oxide ion (O2-).
The ion with a smaller size is F- (fluoride ion) compared to O2- (oxide ion).
The size of an ion depends on the number of protons and electrons it has. Fluoride ion has one less electron than the oxide ion, making it smaller in size.
This trend can be explained by the concept of effective nuclear charge, where the positive charge of the nucleus is partially shielded by other electrons in the atom. As the atomic number increases from oxygen to fluorine, the increase in nuclear charge outweighs the additional electron-electron repulsions, resulting in a smaller size for fluoride ion.
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Fossils
Timelines
Molecular clocks
Molecular clocks use the relationship between the DNA of several groups of organisms to evaluate how long ago they diverged evolutionarily from one another. Therefore, option (4) is correct.
The molecular clock can be described as a figurative term for a technique that utilizes the mutation rate of biomolecules to determine the time when two or more life forms diverged. The biomolecular data used are usually nucleotide sequences for DNA, RNA, or amino acid sequences for proteins.
The benchmarks for calculating the mutation rate are often fossil or archaeological dates. The molecular clock is commonly used in molecular evolution to estimate times of speciation or radiation.
The molecular clock can only give one time period as it cannot assign concrete dates. For viral phylogenetics and ancient DNA studies, the areas of evolutionary biology, the intermediate samples can be utilized to more precisely calibrate the molecular clock.
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Answer is: boron (¹¹B).
1) Carbon (¹²C) is element with atomic number 6 and mass number 12. Atomic number (Z) is the number of protons, which is characteristic of a chemical element.
Z(C) = p⁺ = 6.
A = p⁺ + n°; mass number is the total number of protons and neutrons in a nucleus.
A(C) = 12.
n°(C) = 12 - 6.
n°(C) = 6; number of neutrons.
2) Boron (¹¹B) is element with atomic number 5 and mass number 11.
Z(B) = p⁺ = 5.
A(B) = 11.
n°(B) = 11 - 5.
n°(B) = 6; number of neutrons in boron.