I think that it is helium, but not 100% sure
<span>The amount of
protons is equal to the number of electrons of a chemical element. The atomic
number of an element also determines the number of the protons it contains.
The number of protons is also the same number of electrons. Protons are positively charged, electrons are
negatively charged. To get the number of neutrons, all you need is to deduct
the number of the atomic mass or mass number from the atomic number. Potassium has 19
protons, therefore has 19 electrons as well. The atomic mass of Potassium is
39. So, the number of neutrons Potassium has is 20. </span>
Potassium
Atomic
number: 19
Protons: 19
Electrons: 19
Atomic Mass:
39
Neutron: 20
Nitrogen
Atomic
number: 7
Protons: 7
Electrons: 7
Atomic Mass:
14.007
Neutrons: 7
Oxygen
Atomic
Number: 8
Protons: 8
Electrons: 8
Atomic Mass:
15.99
Neutrons: 8
The rate of effusion of H₂ : 7.2 x 10⁻² m/s
<h3>Further explanation </h3>
Graham's law: the rate of effusion of a gas is inversely proportional to the square root of its molar masses or
the effusion rates of two gases = the square root of the inverse of their molar masses:
or
MW₁ O₂ = 32 g/mol
MW₂ H₂ = 2 g/mol
Pretty sure the answer is A, but you probably shouldn't use Brainly to answer test questions.
The PH of the solution of HCl is calculated as below
Ph= - log H^+
calculate the hydrogen ion concentration
by first write the ionic equation for dissociation of HCl
HCl = H^+ + Cl^-
since the mole ratio between HCl to H^+ is 1:1 the concentration of H^+ =0.01 M
Ph is therefore = - log 0.01 = 2
HCl has a PH of 2
