Answer:
The order is:
F >Be >Li >Ba
Explanation:
Electrons are held in atoms by their attraction to the nucleus which means that to remove an electron from the atom energy is needed.
The ionization energy is the minimum energy necessary to remove an electron from an atom in the gas phase and ground state, the electron removed being the outermost, that is, the furthest from the nucleus. The further away the electron is from the nucleus, the easier it is to remove it, that is, the less energy is needed.
By increasing the atomic number of the elements of the same group, the nuclear attraction on the outermost electron decreases, since the atomic radius increases. Then the ionization energy decreases. In other words, in a group it decreases from top to bottom because the size of the atom increases and it is easier to remove an external electron.
By increasing the atomic number of the elements of the same period, the nuclear attraction on the outermost electron increases, since the atomic radius decreases. Therefore, in a period, as the atomic number increases, the ionization energy increases. In summary, in a period it increases from left to right as the effective nuclear charge increases and it increases thanks to the decrease in the size of the atom.
Taking these considerations into account, the order is:
<u><em>F >Be >Li >Ba</em></u>
Answer: A. 490.48mol
Explanation:
Using the ideal gas equation; PV =nRT
where P = Presssure = 200 atm
V = Volume = 60L
n = Number of moles
R = Gas constant = 0.08206 L.atm/mol/K
T = Temperature = 25 °C + 273 = 298K
Make "n" the subject of the formular;
n = PV / RT
= 200 x 60 / 0.08206 x 298
= 490.73 mol, which is closest to option A. 490.48mol
Answer:
Correct answer is option B ( 3-hexanone )...hope this helps:)
Answer: colliding tectonic plates
Explanation:
Answer:
i) Buffer absorbs H^+ and OH^- ions preventing large changes in pH when small amounts of acid or base is added but when large amounts of acid or base is added there will be a change in pH
ii) absorption of liquid is related to a chemical reaction for a buffer system but it is not related a chemical reaction for a proton( H ) sponge.
Explanation:
<u>i) Buffer like a proton ( H ) sponge </u>
Buffer absorbs H^+ and OH^- ions preventing large changes in pH when small amounts of acid or base is added but when large amounts of acid or base is added there will be a change in pH
The pH of a Buffer follows the Henderson-Hasselbach model
pH = pKa + Log ([A-]/[HA])
when base is added
HA + OH^- -------> A- + H2O
when acid is added
A^- + H^+ ---------> HA
<u>ii) Buffer not like a proton ( H ) sponge</u>
absorption of liquid is related to a chemical reaction for a buffer system but it is not related a chemical reaction for a proton( H ) sponge.