Hey there!:
Molar mass Lead ( Pb ) = 207.2 g/mol
Therefore:
1 mole Pb --------------------- 6.02*10²³ atoms
? moles Pb -------------------- 2.31*10²¹ atoms
moles Pb = ( 2.31*10²¹ ) * 1 / ( 6.02*10²³ ) =
moles Pb = ( 2.31*10²¹ ) / ( 6.02*10²³ ) =
=> 0.00383 moles of Pb
Hope this helps !
Answer:
Correct answer is (D). as a weak acid it can cross the membrane when in its uncharged form.
Explanation:
Aspirin (acetylsalicylic acid, ASA) is an analgesic and anti-inflammatory agent use in the treatment of gentle to moderate pain, inflammation and fever. It is absorb in the stomach and intestine in an unchanged form.
Answer:
Antibodies are types of proteins in the body that can prevent diseases. Once a vaccine is introduced into the bloodstream, it immediately causes the production of antibodies to occur by using T-cells and B lymphocytes, or at least, most vaccines work like that.
Explanation:
Answer:
B) substitution
Explanation:
2,3 dichloropentane is a hydrocarbon that contains two chlorine atoms in its chain. It has a chemical formula: 
. In the compound, two hydrogen atoms has been substituted by two chlorine atoms.
A substitution reaction is a process by which an atom of a compound is being replaced by another atom to form a new compound due to a chemical reaction. This is one of the general properties of alkanes.
Answer:
H₂²⁺(aq) + O₂²⁻(aq) + SO₃²⁻(aq) → SO²⁻₄(aq) + H₂O(l)
Explanation:
H₂²⁺(aq) + O₂²⁻(aq) + Mg²⁺(aq) + SO₃²⁻(aq) → Mg²⁺(aq) + SO²⁻₄(aq) + H₂O(l)
A careful observation of the equation above, shows that the equation is already balanced.
To obtain the net ionic equation, we simply cancel Mg²⁺ from both side of the equation as shown below:
H₂²⁺(aq) + O₂²⁻(aq) + SO₃²⁻(aq) → SO²⁻₄(aq) + H₂O(l)
