What is density?
Chandraprakash G | 2024-April-26
15 mins 🕖
Introduction
It took me a lot of years to comb through hundreds of units and conversions between them to arrive at gram multiplier / Liter calculation, which was much easier to read the data across Solid, Liquid, Gas and even to the pollutant levels of precision, all with ease of understanding due to having a common denominator (Liter).
Density = Mass per unit volume
In simple example,
Density = Amount of matter your could store in 1 Liter of water bottle.
Solid density:
If you melt an Iron bar and fill the 1 liter water bottle, it’ll weigh ~8 kg, So we can call the density of Iron as ~8 kg/Liter (~8 kg/L)
Liquid density:
If you fill the 1 liter water bottle with water then it will weigh 1 kg, hence density of water is 1 kg/L or 1000 g/L
Also if you fill the 1 liter water bottle with coconut oil then it’ll weigh ~0.9 kg (900 g), hence density of coconut oil is 0.9 kg/L or 900 g/L
Gas density:
If you fill the 1 liter water bottle with oxygen gas then it’ll weigh ~1.4 g (1400 mg), hence density of Oxygen gas is ~1.4 g/L or ~1400 mg/L
Basic metric multipliers
Solid density
Unit:
kg/L
Other:
g/cm³
kg = kilogram = 10^3 gram
L = Liter
cm³ = ml
Common solids
kg/L
Wood
0.3 - 1.2
Plywood
0.4 - 1.2
Natural rubber
0.9
Ice
0.91
Human bone
0.9 - 1.4
Plastic
0.9 - 1.4
Human
0.98
Fun Fact:
Density of water is 1 kg/L,
so anything less than that will float in water and anything higher gonna simply sink
Glass
2.4
Marble
2.7
Granite
2.7
Aluminium
2.7
Aluminium being one of the lightest metal as well as the most abundant in earth’s crust is known for it’s uses in aircraft body as well as in high performance vehicles like Tesla
Aluminium can
Diamond
3.5
Iron
8
As you can see the the density of Iron at 8 kg/L, which is over 3X the density of Aluminium.
So if you try to lift a mould made of Iron vs Aluminium, you gonna notice the difference pretty significantly.
Copper
9
Silver
10.5
Lead
11.3
Mercury
13.5
While density of water stands at 1 kg/L,
density of mercury in liquid form is 13.5 kg/L, especially while you try to lift a liter of mercury in a bottle or in a vessel your brain sure gonna get confused on why this shiny liquid weighs heavier than Iron, and it gonna get lot of time getting used to the feeling.
Gold
19.3
Gold is one of the heaviest elements in the periodic table, Gold in it’s purest form is pretty heavy at ~19 times the weight of water if filled in a water bottle and even 2.5X the weight of Iron!
Gold bar
Platinum
21.5
Osmium
22.6
kg/L
Liquid metal - Mercury
Liquid density
Unit:
g/L
Other:
kg/m³
g = gram
L = Liter
m³ = 1000 L
Common liquids
g/L
Liquid Nitrogen
800
Liquid Hydrogen
70
Petrol
750
Diesel
850
Coconut oil
920
Water
1000
Milk
1030
Honey
1400
Mercury
13,500
g/L
Sea water
1025
Liquid Oxygen
1140
Liquid Helium
125
Gas density
Unit:
mg/L
Other:
g/m³
mg = milligram = 10^-3 gram
L = Liter
m³ = 1000 L
Common gasses
mg/L
Hydrogen
90
mg/L
Hydrogen (350 kg/cm²)
25,000
Hydrogen (700 kg/cm²)
40,000
Oxygen
1430
Nitrogen
1250
Wood
0.3 - 1.2
Wood
0.3 - 1.2
Wood
0.3 - 1.2
Wood
0.3 - 1.2
g/L
0.090
25
40
1.43
1.25
0.3 - 1.2
0.3 - 1.2
0.3 - 1.2
0.3 - 1.2
Pollution density
Unit:
ng/L
Other:
μg/m³
ng = nanogram = 10^-9 gram
μg = microgram =10^-6 gram
L = Liter
Pollutants
ng/L
Wood
0.3 - 1.2
TDS meter which shows the water hardness measures it in mg/L (or ppm) value
ng/L
Energy density
Gravimetric:
Wh/kg
Volumetric:
Wh/L
Wh = Watt hour
kg = kilogram
L = Liter
1 kg/cm² = ~1 bar
Energy source
Wh/kg
Wh/L
Lead acid
0.3 - 1.2
0.3 - 1.2
Ni Ca
0.3 - 1.2
0.3 - 1.2
Li ion - NCM
0.3 - 1.2
0.3 - 1.2
Li ion - LFP
0.3 - 1.2
0.3 - 1.2
Li ion - LTO
0.3 - 1.2
0.3 - 1.2
H2 gas (700 kg/cm²)
0.3 - 1.2
0.3 - 1.2
Liquid hydrogen
0.3 - 1.2
0.3 - 1.2
Petrol | Gasoline
0.3 - 1.2
0.3 - 1.2
Diesel
0.3 - 1.2
0.3 - 1.2
LPG
0.3 - 1.2
0.3 - 1.2
LNG
0.3 - 1.2
0.3 - 1.2
H2 gas (300 kg/cm²)
0.3 - 1.2
0.3 - 1.2