China 
Africa 
- Newton's law of cooling
- Newton's method
- Newton-metre
- Newton-seconds
- Newtonian fluids
- Next-generation firewall
- Next-generation lithography
- Nf-κb
- Nfatc1
- Nginx
- Ngspice
- NiMH
- Niacin
- Nibble
- Nicastrin
- Nice
- Nichrome
- Nickel
- Nickel acetate
- Nickel allergy
- Nickel aluminide
- Nickel carbonate
- Nickel chloride
- Nickel compounds
- Nickel electroplating
- Nickel fluoride
- Nickel hydride
- Nickel hydroxide
- Nickel mines
- Nickel oxide hydroxide
- Nickel plated
- Nickel silicide
- Nickel silver
- Nickel steel
- Nickel sulfate
- Nickel sulfide
- Nickel-cadmium batteries
- Nickel-cadmium battery
- Nickel-metal hydride battery
- Nickel-zinc battery
- Nickeline
- Nickelocene
- Nicol prisms
- Nicotiana benthamiana
- Nicotinamide
- Nicotine
- Nicotine salt
- Nicotinic acetylcholine receptor
- Nicrosil
- Nictitating membrane
- Nidogen
- Nidovirales
- Niederreiter cryptosystem
- Nife hydrogenase
- Night
- Night shift
- Night sweats
- Night vision
- Night vision goggles
- Nile Red
- Nilpotent
- Nilpotent matrix
- Nimonic
- Nine-point stencil
- Ninhydrin
- Niobate
- Niobium
- Niobium alloy
- Niobium chloride
- Niobium-tin
- Niobium-titanium
- Niosomes
- Nipah virus
- Nipple
- Nipple discharge
- Nisil
- Nisin
- Nital
- Nitarsone
- Nitazoxanide
- Niter
- Nitrate
- Nitrate esters
- Nitrate radical
- Nitrate reductase
- Nitratine
- Nitration
- Nitrene
- Nitrenium ion
- Nitric
- Nitric acid
- Nitric oxide
- Nitric oxide synthase 2
- Nitric-oxide reductase
- Nitriding
- Nitrification
- Nitrifying bacteria
- Nitrile
- Nitrile hydratase
- Nitrile rubber
- Nitrilotriacetic acid
- Nitrite
- Nitrite reductase
- Nitro
- Nitro compounds
- Nitrobenzene
- Nitrofen
- Nitrofuran
- Nitrofurantoin
- Nitrofurazone
- Nitrogen assimilation
- Nitrogen compounds
- Nitrogen cycle
- Nitrogen deficiency
- Nitrogen dioxide
- Nitrogen fixation
- Nitrogen generators
- Nitrogen ice
- Nitrogen laser
- Nitrogen mustard
- Nitrogen narcosis
- Nitrogen oxides
- Nitrogen rejection unit
- Nitrogen trifluoride
- Nitrogen-13
- Nitrogen-vacancy center
- Nitrogenase
- Nitroglycerin
- Nitroglycol
- Nitroimidazole
- Nitromethane
- Nitronic
- Nitronium
- Nitronium ion
- Nitrophenol
- Nitroprusside
- Nitrosamines
- Nitrosation
- Nitrosomonas europaea
- Nitrosonium
- Nitrosonium tetrafluoroborate
- Nitrosourea
- Nitrosylation
- Nitrotoluene
- Nitrous
- Nitrous acid
- Nitrous oxide
- Nitrous-oxide reductase
- Nitroxide
- Nitroxide mediated radical polymerization