Answer:
a. H0: σ2 ≤ 625
Explanation:
In statistics, a null hypothesis is an assumption that is used to affirm or deny a particular event that is related to one or more parameters of a population or sample. It refer tos the statement that the researcher is working to reject, is the commonly accepted fact, it is the opposite of the alternate hypothesis which is the statement the researcher is working to prove as true.
So in this case, we are trying to prove that the variance is significantly more than 625, so that would be our alternate hypothesis, therefore, the already accepted fact is that the variance is less or equal than 625, which is the null hypothesis.
Answer:
Strontium
Explanation:
The atomic number of strontium is 38.
It has 38 electrons.
It is alkaline earth metal. It has two valance electrons.
Strontium loses its two electrons and form cation with +2 charge.
Electronic configuration;
Sr₃₈ = [Kr] 5s²
The valance electrons present in 5s are lost by strontium atom and form Sr⁺² cation.
it is yellowish-white metal.
It is highly reactive.
It form salt with halogens.e.g
Sr + Br₂ → SrBr₂
IT react with oxygen and form oxide.
2Sr + O₂ → 2SrO
this oxide form hydroxide when react with water,
SrO + H₂O → Sr(OH)₂
With nitrogen it produced nitride,
3Sr + N₂ → Sr₃N₂
With acid like HCl,
Sr + 2HCl → SrCl₂ + H₂
Since Group 2 alkali earth metals have 2 valence electrons, they tend to lose those 2 when forming ionic bonds. And the Loss of Electrons = Oxidation (L.E.O. for short). Therefore this group, including Mg and Ca, have an oxidation of [+2].
So the correct answer is C) +2
Answer:
b consumers eat producers
Explanation:
In a food chain, the consumers are living organisms that eat organisms from a different population. Examples are herbivores like goats.
Producers make their own food in the food chain. Examples are plants.
The relationship between consumer and producers is hence that consumers consume / eat producers. Goats eat grass.
The correct option is;
b consumers eat producers
