Answer:D - adding a catalyst
Explanation:
atomic mass=percentage of isotope a * mass of isotope a + percentage of isotope b * mass of isotope b+...+percentage of isotope n * mass of isotope n.
Data:
mass of isotope₁=267.8 u
percentage of isotope₁=90.3%
mass of isotope₂=270.9 u
percentage of isotope₂=9.7%
Therefore:
atomic mass=(0.903)(267.8 u)+(0.097)(270.9 u)=
=241.8234 u + 26.2773 u≈268.1 u
Answer: the mass atomic of this element would be 268.1 u
Ammonium chloride is the correct name for NH4CL
the combustibility of calcium is relitivly high
Answer : The volume of calcium hydroxide is, 32.89 ml
Explanation :
Using neutralization law,
where,
= basicity of an acid = 1
= acidity of a base = 2
= concentration of hydrobromic acid = 0.389 M
= concentration of calcium hydroxide = 0.0887 M
= volume of hydrobromic acid = 15 ml
= volume of calcium hydroxide = ?
Now put all the given values in the above law, we get the volume of calcium hydroxide.
Therefore, the volume of calcium hydroxide is, 32.89 ml