This is a fill in the blanks question.
This is where the blanks are: A __________ is scientific knowledge established through direct observation and remains constant. Scientific knowledge can change when scientists _____________
The answer is followiing.
Answer: A <em>law</em> is scientific knowledge established through direct observation and remains constant. Scientific knowledge can change when scientists <em>find new evidence</em>.
Explanation:
A scientific law describes the relation (usually in mathematical terms) of natural phenomena and is supported by numerous observations and experiments. The laws are established when all the observations and result show that all the facts obey the same relation. For instance, the Universal law of gravitation: all the objects are attracted with a force that is directly proportional to the product of their masses and inversely related to the square of the distance that separates them: in lay terms, everything that goes up has to go down, and you do not expect that when a parachutist jumps out of an airplane he or she does not fall on the ground.
On the other hand, a scientific theory, although is an explanation that has been repeatedly tested and verified, is always under scientific scrtutiny and, as additional evidence is gathered it can be modified or replaced by a new theory. That is why it is said that scientific theories have to be testable and falsiable: if it is not testable and falsiable then it is not a scientific theory.
Scientific theories are aimed to describe, explain and make predictions about the objectivable world.
Equation: 2H₂ + O₂ → 2H₂O
Now, Given mass of Oxygen = 192 g
Molar mass of Oxygen = 16 g/mol
No. of moles in Oxygen = 16/192 = 0.0833
Now, for every mole of Oxygen, 2 mole of Hydrogen will form,
so, Number of moles of Hydrogen = 0.0833 * 2 = 0.167
Given mass = Number of Moles * Molar mass
Given mass = 0.167 * 2
m = 0.33 g
In short, Your Answer would be: 0.33 g
Hope this helps!
Solubility
product constants are values to describe the saturation of ionic compounds with
low solubility. A saturated solution is when there is a dynamic equilibrium
between the solute dissolved, the dissociated ions, the undissolved and the
compound. It is calculated from the product of the ion concentration in the
solution. For the generic salt, AB2, the dissociation would be as
follows:<span>
AB2 = A2+ + 2B-
So, the expression for the solubility product would be:
Ksp = [A2+] [B-]^2
</span>Ksp = [x] [2x]^2 = 4x^3
<span>
where x = </span><span>3.72×10^−4 M
</span><span>
Ksp = </span>4( 3.72×10^−4 )^3
Ksp = 2.06x10^-10 M^3
The solubility product constant of AB2 would be Ksp = 2.06x10^-10 M^3.
Physical properties
the characteristics (properties) that can be observed without changing the identity of a substance
Examples of physical properties
mass, color, size, volume, texture, density, state of matter, boiling point, melting point
