The name transition metal refers to the position in the periodic table of elements. The transition elements represent the successive addition of electrons to the d atomic orbitals of the atoms. In this way, the transition metals represent the transition between group 2 (2A) elements and group 13 (3A) elements.
The mass of magnesium in 
atoms is 240 g.
Answer: Option A
<u>Explanation:</u>
First, we have to convert the atoms to moles of magnesium.
We know that atoms are present in 1 mole of magnesium. So,
Thus,
Thus, 240 g of Magnesium is present in atoms.
Answer:
Francium is hypothesized to be the most reactive metal, but so little of it exists or can be synthesized, and the longest half-life of its most abundant isotope is 22.00 minutes, so that its reactivity cannot be determined experimentally.
Explanation:
Francium is an alkali metal in group 1/IA. All alkali metals have one valence electron. As you go down the group, the number of electron energy levels increases – lithium has two, sodium has three, etc..., as indicated by the period number. The result is that the outermost electron gets further from the nucleus. The attraction from the positive nucleus to the negative electron is less. This makes it easier to remove the electron and makes the atom more reactive.
Experimentally speaking, cesium (caesium) is the most reactive metal.
Answer:
Option b. 9.59
Explanation:
First, let us calculate the pH. This is illustrated below:
[H3O+] = 3.9 x 10-5 M
pH = —Log [H3O+]
pH = —Log [3.9 x 10-5]
pH = 4.41
Recall: pH + pOH = 14
4.41 + pOH = 14
Collect like terms
pOH = 14 — 4.41
pOH = 9.59
