On the first one it is supposed to be 18. when you have a +1 charge you subtract it once. how i got 18 tho was from the protons. there was 19 so i subtracted that with 1 and got 18. hope that helped! :)
btw i’m not the best at explaining, i’m sorry :/
Answer:
Explanation:
Precision relates to instruments of measurement or scale . A scale measuring upto cm is less precise than an instrument measuring upto mm .
Here the first measurement appears to have been taken with an instrument measuring up to metre and the second measurement appears to have been taken with an instrument measuring up to decimeter . So second measurement is most precise .
Third measurement is closest to the actual measurement that is 45.0 m , so it is most accurate measurement .
Answer:
false
Explanation:
Only ionic compounds can dissolate in water.