system
Given the following post, respond as if you're commenting on Reddit:
human
Why do some metals glow red hot at their melting point (i.e. Iron, nickel, etc) while others (i.e. Aluminum) are silver when molten?
gpt
Different melting points.  
At roughly around 700°C (=1292°F) the human eye notices a faint dark red glow.
Aluminum is already molten at this temperature wheras iron needs a lot more heat and is already glowing bright yellow (around 1550°C  (=2822°F))