Hydrogen, helium, lithium,
Copper substance cannot be decomposed by a chemical change.
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- When heated, the copper to carbonate breaks down into copper to oxide. The copper carbonate, which is dark in colour, releases carbon dioxide as well.Because they are the simplest chemically, elements cannot be broken down by chemical processes.
- Elements are those pure compounds that cannot be broken down by reactions, heating, electrolysis, or other common chemical processes. Examples of elements are oxygen, gold, and silver. Its makeup stays the same, though. One instance of a physical change is melting. A physical change is when a sample of matter experiences a change in some of its qualities but not in its identity. Water turns into water vapour when it is heated.
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Answer:
A
Explanation:
it has an arrow symbolizing direction because a vector quantity has both magnitude and direction.
Answer:
3.2L
Explanation:
PV=nRT
since pressure and temperature are held constant we have V=nR
R is a constant also,
Thus; 
v1=1.5L , n1=3mol, n2=1.4mol
v2=
v2=3.2L
<u>Answer:</u> The molecular weight of protein is 
<u>Explanation:</u>
To calculate the concentration of solute, we use the equation for osmotic pressure, which is:
or,
where,
= Osmotic pressure of the solution = 0.0861 atm
i = Van't hoff factor = 1 (for non-electrolytes)
= mass of protein = 400 mg = 0.4 g (Conversion factor: 1 g = 1000 mg)
= molar mass of protein = ?
= Volume of solution = 5.00 mL
R = Gas constant = 
T = temperature of the solution = ![25^oC=[25+273]K=298K](https://tex.z-dn.net/?f=25%5EoC%3D%5B25%2B273%5DK%3D298K)
Putting values in above equation, we get:
Hence, the molecular weight of protein is
