Answer:
Explanation:
Carbon dioxide is the answer I think.
Hope it helps...
Answer:
Water boils - physical change
Salt dissolves in water- chemical change
Milk turns sour- chemical change
metal rusts - chemical change
Explanation:
A chemical change refers to changes that are irreversible and the process involves the evolution of heat along with the formation of a new substance, examples include;Salt dissolves in water, Milk turns sour, metal rusts etc
The boiling of water is a physical change. The water can be cooled and the vapour condensed,hence, the boiling of water is a physical change.
Physical changes are easily reversible and no new substance is formed.
Allergies arise when a foreign material such as pollen, bee venom or pet dander responds to your immune system or a food that in most people does not cause a reaction. Substances known as antibodies are formed by your immune system.
Answer:
C
Explanation:
All thing in option c is flammable
Answer:
vHe / vNe = 2.24
Explanation:
To obtain the velocity of an ideal gas you must use the formula:
v = √3RT / √M
Where R is gas constant (8.314 kgm²/s²molK); T is temperature and M is molar mass of the gas (4x10⁻³kg/mol for helium and 20,18x10⁻³ kg/mol for neon). Thus:
vHe = √3×8.314 kgm²/s²molK×T / √4x10⁻³kg/mol
vNe = √3×8.314 kgm²/s²molK×T / √20.18x10⁻³kg/mol
The ratio is:
vHe / vNe = √3×8.314 kgm²/s²molK×T / √4x10⁻³kg/mol / √3×8.314 kgm²/s²molK×T / √20.18x10⁻³kg/mol
vHe / vNe = √20.18x10⁻³kg/mol / √4x10⁻³kg/mol
<em>vHe / vNe = 2.24</em>
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I hope it helps!
