Answer:
Choice A: Approximately
joules.
Explanation:
Apply the famous mass-energy equivalence equation to find the energy that correspond to the
kilograms of mass.
,
where
stands for energy,
stands for mass, and
is the speed of light in vacuum.
The speed of light in vacuum is a constant. However, finding the right units for this value can simplify the calculations a lot. What should be the unit of
?
The mass given is in the appropriate SI unit:
Mass is in kilograms.
Thus, proceed with the speed of light in SI units. The SI unit for speed is meters per second. For the speed of light,
.
Apply the mass-energy equivalence:
.
The unit of energy is not in joules. Don't be alerted. Consider the definition of a joule of energy. One joule is the work done on an object when a force of one newton acts on the object in the direction of the force through the distance of one meter. (English Wikipedia.)
.
However, a force of one newton is defined as the force required to accelerated an object with a mass of one kilogram (not gram) at a rate of one meter per second squared. (English Wikipedia.)
.
In other words, the mass defect here is also
.
Answer:
It would be an isotope.
Background Information:
Isotopes are typically elements that have a different number of protons than neutrons. The atomic mass is the total number of protons and neutrons. The atomic number is the number of protons.
Explanation:
If the atomic number is the number of protons that means that this particular element has 8 protons. If the atomic mass is the total number of protons and neutrons then we can simply take away the amount of protons from that number, 18 - 8 = 10. If we take protons away from the number of protons and neutrons we are left with the number of neutrons. So there are 10 neutrons. Because there are 8 protons and 10 neutrons, or a different amount of neutrons and protons we know that this particular atom is an isotope.
68.7g
molar mass of Ba(137.327)x (.500)= 68.6635
.500 has 3 sig figs.
Answer:
MgCl2 (s) + Li2CO3 (s) ==> MgCO3 (s) + 2LiCl (aq)
Double Replacement
Explanation:
MgCl2 (s) + Li2CO3 (s) ==> MgCO3 (s) + 2LiCl (aq)
Double Replacement
Halogens are Soluble
Carbonates are Insoluble
This reaction DOES take place.