Answer:
63. 55 amu
Explanation:
Copper is known to exist in two different isotopes which are Cu-63 and Cu-65.
Cu-63 has an atomic mass of 62.93 amu and it has an abundance of 69.15%.
Similarly,
Cu-65 has an atomic mass of 64.93 amu and it has an abundance of 30.85%
Therefore, using the weighted average mass method, the atomic mass of copper is:
Atomic mass of copper = (0.6915*62.93) amu + (0.3085*64.93) amu = 43.52 amu + 20.03 amu = 63.55 amu
Thus, the atomic mass of copper (express in two decimal places) is 63.55 amu
Answer:
a
Explanation:
the answer is a i'm pretty sure it might be wrong tho i'm sorry
Answer:
Answers in explanation.
Explanation:
30. A (A chemical changes changes the chemical properties)
31. C (rusting is an example of a chemical change
32. B (A reaction requires energy, so some energy will be expelled)
33. B (Color change is an example of a chemical change)
34. A (The law of the conservation of mass: Mass and Energy cannot be created nor destroyed)
Answer:
Explanation:
Standard enthalpy of combustion (ΔH∘C) is the enthalpy change when 1 mole of a substance burns under standard state conditions;
