Given :
An atom of a certain element has 12 protons, 14 neutrons, and 2 valence electrons.
To Find :
The name of this element.
Solution :
We know, element with atomic number ( number of protons ) 12 and valance electrons is Magnesium.
Now, isotope of magnesium of proton with 14 neutrons is Mg-16 .
Therefore, name of element is Mg-16 .
Hence, this is the required solution.
Picoliter is a unit of measurement for liquids.
One picoliter = 1×10⁻⁹ mililiters
So:
19 mL ---- x pL
1×10⁻⁹ mL ---- 1 pL
1×10⁻⁹x = 19
x = 1,9 × 10¹⁰ pL
or 19,000,000,000 pL
Answer: 1.9 × 10¹⁰ pL
Answer: 9.09 %
Explanation:
To calculate the percentage concentration by volume, we use the formula:
Volume of ethanol (solute) = 30 ml
Volume of water (solvent) = 300 ml
Volume of solution= volume of solute + volume of solution = 30+ 300 = 330 ml
Putting values in above equation, we get:
Hence, the volume percent of solution will be 9.09 %.
The law of conservation of mass dictates that the total mass of reactants must be equal to the total mass of the products. Thus:
mass(MgO) = mass(Mg) + mass(O)
mass(MgO) = 24 + 16
mass(MgO) = 40 g
The third option is correct.
