<span>Kind of substance besides water:
The best example of hydrogen bonding excluding water is DNA. The two strands of polymers are connected by hydrogen bonds between the nucleotide bases</span>.
Physical: ripping paper, braking a stick, cake batter mixing
Chemical: burning paper, spoiled milk, a penny turning green
Closer is bigger................
Hydrofluoric acid is not a strong acid despite being a hydrohaulic acid (hydrogen and a halogen). HF is highly corrosive and can be used to dissolve most oxides