Answer:
C
Explanation:
This experiment by Rutherford involved the firing of alpha particles at gold foils. It is also. called the gold foil experiment.
He fired these alpha particles at different points. He noticed that at some points, there were deflections, while at some other points, there were no deflections. It is necessary to state that these alpha particles are positively charged. For there to be a deflection, there must have been a kind of repulsion between the gold foil and the alpha particles.
From the basic physics of like repels like, he knew for sure that there must be dense positive core in the atom that is causing the deflection of the alpha particles. This enabled him to come up with the theory that the atom contained a small dense positive core called the nucleus
The half life of a radioactive element is the time needed to the element to decay and reach the half amount of the initial amount. Here we have a radioisotope element which decays its half from 10,000 to 5,000 in two days. Therefore, its half life is 2 days.
Answer: m= 85.8 g CH2O
Explanation: First step is convert the molecules of CH2O to moles using the Avogadro's Number.
1.72x10²⁴ molecules CH2O x 1 mole CH2O / 6.022x10²³ molecules CH2O
= 2.86 moles CH2O
Next is convert the moles of CH2O to mass using the molar mass of CH2O
2.86 moles CH2O x 30 g CH2O / 1 mole CH2O
= 85.8 g CH2O
Mass number is the sum of protons and neutrons.
Atomic number is the total number of protons present.
Mass number = protons + neutrons
Atomic number = protons present.
From the above equations we can conclude that,
Atomic number= Mass number- neutrons.
Thus we can find out the atomic number by subtracting the number of neutrons from the mass number.
Answer:
1. HBr>HCl> H2S >BH3
2.K_a1 very large — H2SO4
K_a1= 1.7 x 10^−2 — H2SO3
K_a1 = 1.7 x 10^−7 — H2S
Explanation:
As one goes down a row in the Periodic Table the properties that determine the acid strength can be observed.
The atoms get larger in radius meaning that in strength, the strength of the bonds get weaker, conversely meaning that the acids get stronger.
For the halogen-containing acids above following the rows and periods, HBr has the strongest bond and is the strongest acid and others follow in this order.
HBr>HCl> H2S >BH3
Acid Dissociation Constant provides us with information known as the ionization constant which comes in handy to measure the acid's strength. The meaning of the proportions are thus, the higher the Ka value, the stronger the acid i.e. it liberates more number of hydrogen ions per mole of acid in solution.
In solution strong acids completely dissociate hence, the value of dissociation constant of strong acids is very high.
Following the cues above on Ka;
K_a1 very large — H2SO4
K_a1= 1.7 x 10^−2 — H2SO3
K_a1 = 1.7 x 10^−7 — H2S
