The mass number, also known as an atomic mass number or nucleon number, refers to the total number of neutrons and protons (in a combination known as nucleons) in an atomic nucleus. It determines the atomic mass of atoms. However, while calculating the mass number, the small contribution of mass from electrons is ignored.
Mass number is equal to Number of protons + Number of neutrons
Mass number = 11 + 7 = 18.
Hence, the correct answer is 18.
Answer:
There are two main types of physical weathering: <u>Freeze-thaw</u> occurs when water continually seeps into cracks, freezes, and expands, eventually breaking the rock apart. <u>Exfoliation</u> occurs as cracks develop parallel to the land surface a consequence of the reduction in pressure during uplift and erosion.
Answer:
This planet contains an atmosphere and ocean, so it would be A im guessing.
At 100C the water becomes a gas. So at normal pressure water can't be above 100C
Answer:
Post reproductive isolation → Hybrid sterility
Explanation:
The biological concept of species states that individuals of a species can not mate and reproduce with individuals of another species. But if they get to reproduce, the progeny will not be viable or fertile. There will not be any reproductive success.
There are different reproductive isolation mechanisms, which are barriers that inhibit or interrupt the genetic flow between different species.
Reproductive barriers are isolation mechanisms that prevent mating between two or more species. The prezygotic mechanism avoids fertilization between individuals of different species, while the postzygotic mechanism impedes the zygote to develop and reach the adult stage.
Postzygotic mechanisms or barriers include
- Hybrid inviability,
- Hybrid sterility,
- Hybrid decreased viability or fertility,
- Cytoplasmic interactions.
In the exposed example, it seems that the mountains separating the frogs´ populations made a place for the development of postzygotic barriers, specifically hybrid sterility. Frogs from one population get to mate and produce offspring with the frogs of the other population, but their progeny is sterile.
