A catalyst speeds up the rate of reaction so the answer is B.
A molecule of hydrogen is formed by two hydrogen atoms, that is a fact.
How does it work? When two atoms, known as "diatomic" pair with another in a bond known non-polar covalent bonds. Where they equally share electrons. A Hydrogen atoms needs 1 more electrons to fill its first shell fully and have a full valence shell. So if two H's share their electrons, they'll both have a full V-Shell!
That's the basics of both the H-H bond and all the other diatomic bonds as well.
Answer is: a. Rubidium (Rb) is more reactive than strontium (Sr) because strontium atoms must lose more electrons.
The ionization energy (Ei) is the minimum amount of energy required to remove the valence electron, when element lose electrons, oxidation number of element grows (oxidation process).
Alkaline metals (group 1), in this example rubidium, have lowest ionizations energy and easy remove valence electrons (one electron), they are most reactive metals.
Earth alkaline metals (group 2), in this example strontium, have higher ionization energy than alkaline metals, because they have two valence electrons, they are less reactive.
Rubidium electron configuration: ₃₇Rb 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4p⁶5s¹; one valence electron is 5s¹ orbital.
Strontium electron configuration: ₃₈Sr 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4p⁶5s²; two valence electrons is 5s² orbital.
The correct option is A.
A chemical reaction is said to have reached an equilibrium stage if the rate of reaction of the forward reaction is equal to the rate of reaction of the reverse reaction. Two way arrows are usually used to depict equilibrium reactions. These arrows indicate that the chemical reaction can move both ways. At the equilibrium point the concentrations of both the reactants and the products are equal.
To solve this we assume
that the gas inside the balloon is an ideal gas. Then, we can use the ideal gas
equation which is expressed as PV = nRT. At a constant pressure and number of
moles of the gas the ratio T/V is equal to some constant. At another set of
condition of temperature, the constant is still the same. Calculations are as
follows:
T1 / V1 = T2 / V2
V2 = T2 x V1 / T1
V2 = 308.15 x 7.80 / 698.15
V2 =3.44 L