Almost always, the first way in which biology researchers present the results of their latest research is to discuss the results of previous research that they want to build off of.
Least dense means the one that is at the top. Wood floats on top of water, so wood would be the least dense. Water has a density of 1 and the others would all sink, so they're more dense. The answer is wood
PH = -log [H+]
pH = -log (1.0x10^-4) = -(-4) = 4 or A
What element has the same number of orbits as Hydrogen? Why? Do they have similar properties, why?
Answer:
Helium
Explanation:
Helium has the same number of orbitals as hydrogen because they belong to the same period on the periodic table.
Periods are the horizontal arrangement of elements. Elements in the same period are known to have the same number of electronic shell or orbitals.
In period 1 where we have just Hydrogen and Helium, the number of orbitals is 1.
For properties of a specie, elements in the same group which are the vertical arrangement of elements have the same properties. Since both Hydrogen and helium are in different groups, their properties differ.
The Earth is divided into three chemical layers: the Core [Inner Core (D) and Outer Core (C)], the Mantle (B) and the Crust (A). The Core is predominantly composed of iron and nickel. Even after 4.5 billion years of cooling, the Earth's core remains very hot.
