Answer:
e.iv, iii, i, ii
Explanation:
Be has electron configuration of 1s^2 2s^2. During bond formation, one 2s electron is promoted to a 2p orbital. Hence two hybrid sp beryllium orbitals are formed. These two hybrid orbitals are used in sigma bond formation to fluorine atoms.
Recall that fluorine has filled 2p orbitals containing lone pairs of electrons. These filled orbitals can interact with the unhybridized 2p-orbitals on beryllium to form pi bonds. This is the reason for the sequence of events chosen in the answer.
Explanation:
According to the Bronsted-Lowry conjugate acid-base theory:
An acid is defined as a substance which looses donates protons and thus forming conjugate base.
A base is defined as a substance which accepts protons and thus forming conjugate acid.
For example:
Here, 
is loosing a proton, thus it is considered as an acid and after losing a proton, it forms 
which is a conjugate base.
And, 
is gaining a proton, thus it is considered as a base and after gaining a proton, it forms 
which is a conjugate acid.
Answer:
(B) Her results are both precise and accurate.
Explanation:
In Chemistry, Accuracy refers to how close a measurement is to it's standard value or known value. On the other hand, Precision means how close two measurement are to each other regardless whether the results are accurate or not.
In the above question, all the above results are very close to each other. That's why the results are Precise to each other. All the results are close enough to the actual value of the experiment. That's why the result are also accurate.
Answer:
double-protected
Explanation:
If a package is inside a package, the item inside the second package is double-protected, because the outer package will keep it safe.
Hope this helps!
Answer:
H2SO4(aq) + MgO(s) → H2O(l) + MgSO4(aq)
Explanation:
We must recall that the oxides of metals are bases. These metal oxides can react with dilute acids to yield salt and water.
Bearing that in mind, we want to obtain magnesium sulfate from a metal oxide and dilute acid.
In this case we need magnesium oxide and dilute sulphuric acid. The reaction occurs as follows;
H2SO4(aq) + MgO(s) → H2O(l) + MgSO4(aq)
