Answer:
D
Explanation:
The unit used to measure atomic mass is the atomic mass unit (amu). A single amu is equivalent to 1/12 the mass of an atom from the carbon-12 isotopIsotopes with different numbers of protons and neutrons will have an actual mass slightly different from the atomic mass calculated in atomic mass units.
Answer: 406 hours
Explanation:

where Q= quantity of electricity in coloumbs
I = current in amperes = 39.5 A
t= time in seconds = ?
The deposition of copper at cathode is represented by:

Coloumb of electricity deposits 1 mole of copper
i.e. 63.5 g of copper is deposited by = 193000 Coloumb
Thus 19.0 kg or 19000 g of copper is deposited by =
Coloumb

(1hour=3600s)
Thus it will take 406 hours to plate 19.0 kg of copper onto the cathode if the current passed through the cell is held constant at 39.5 A
Answer:
Element Atomic Number Atomic Mass
Nickel 27 58.6934
Cobalt 28 58.9332
Copper 29 63.546
Zinc 30 65.39
Explanation:
sound wave cannot travel without a medium.
(2) They tend to lose electrons easily when bonding is the correct answer.
All metals have either one, two, or three valence electrons. Therefore, they tend to lose these valence electrons in order to have eight valence electrons like noble gases do.
Hope this helps~