Scheme 16.
(a): N20 (Ih); (b): N20 (D5v); (c): N20 (D5); (d): N20 (C2).
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.