Calculate the [H +] in a 0.028 M solution of HCN, K a = 6.2 × 10 –10. a.
1.0 × 10–7 M
b.
4.2 × 10–6 M
c.
1.7 × 10–11 M
d.
8.3 × 10–6 M
e.
none of these

answer by yourhope:

how do models compare to real-world objects?

d. most models represent a real-world object in a simpler way.

: )

they it depends on if one believes about radioactivity, they make a geiger counter beep but maybe it was going to beep anyway electronics do wierd things all the time or it was programmed to beep near certain metals.