Answer: The volume of 
required is 25.0 ml
Explanation:
According to the neutralization law,
where,
= basicity 
= 1
= molarity of solution = 2.00 M
= volume of solution = 50.0 ml
= acidity of = 1
= molarity of solution = 4.00 M
= volume of solution = ?
Putting in the values we get:
Therefore, volume of required is 25.0 ml
Answer:
20 amu
Explanation:
An atom consist of electron, protons and neutrons. Protons and neutrons are present with in nucleus while the electrons are present out side the nucleus.
All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other. For example if neutral atom has 6 protons than it must have 6 electrons. The sum of neutrons and protons is the mass number of an atom while the number of protons are number of electrons is the atomic number of an atom.
Atomic mass = Number of protons + number of neutrons
Atomic number = Number of electrons or number of protons.
In given question it is stated that atom has 11 electrons and -1 charge it means this atom has 12 electrons in neutral state.
Thus it has 12 protons because number of electrons and protons are always equal.
Atomic mass of given atom:
Atomic mass = Number of protons + number of neutrons
Atomic mass = 12 + 8 = 20 amu
I think the answer is (1) Co. Because the element of Cobalt also has 2 electrons at the outer layer which is the same as Calcium. And the outer layer is an important factor which can affect the property of an element.
13111 is already an integer (whole number). It also can be expressed as 1 ton or 13111000g.
The dew point would be about 22 . (this is C )
