All you need to do is to look at both sides of the equation and see who has the same element, state, coefficient, and charge and those will be your spectator ions.
In this question, the spectator ions would be 
and 
.
Set up your units to algebraically cancel out the original unit, and end up with the units of the answer in the final numerator. We'll first convert to moles by using Avogadro's number, then the atomic mass of tungsten (W) from the periodic table, since the mass, in grams, of one mole of any element is the atomic mass number:
2.1x10∧24 atoms W x (1 mole/6.022x10∧23 atoms) x (183.84g/1 mole) = 641.089 grams
Since your given number has only two significant figures (2.1), your answer should also only express in 2 sig figs: 6.4x10∧2 grams
Answer:
B. Cu (s) +Ni(NO3)2 (aq) - 2CuNO3 +Ni (s)
Explanation:
the above reaction is a substitution reaction
Answer:
6000
Explanation:
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