If the angle is either 0 or 180, that means that there is either negative or positive work, so A and D are not correct.
If the angle is 45, then there is still some work involved.
The only option where there is no work done by a force is B. when the angle is between the force and displacement is 90.
Answer:
19.264×
atoms are present in 3.2 moles of carbon.
Explanation:
It is known that one mole of each element is composed of Avagadro's number of atoms. This is same for all the elements in the periodic table.
So, as 1 mole of any element = Avagadro's number of atoms = 6.02× atoms
It is as simple as understanding a dozen of anything is equal to 12 pieces of that object.
As here the moles of carbon is given as 3.20 moles, the number of atoms in this mole can be determined as below.
1 mole of carbon = 6.02 × atoms
Then, 3.20 moles of carbon = 3.20 × 6.02 × atoms
Thus, 19.264× atoms are present in 3.2 moles of carbon.
Answer:
B.
Explanation:
Propanal is an organic compound with the formula CH3CH2CHO. Aldehyde is colorless, flammable and a slightly fruity odor.
The mass of a present which has a density of 2.15 kg/L and volume of 3650 mL is 7.74 kg.
<h3>How do we calculate mass?</h3>
Mass of any substance will be calculate by using the density and volume by using the below equation as:
Density = Mass / Volume
Given that,
Density of Christmas present = 2.15 kg/L
Volume of present = 3,650 mL = 3.6L
On putting values, we get
Mass = (2.15)(3.6) = 7.74
Hence required mass of Christmas present is 7.74 kg.
To know more about density, visit the below link:
brainly.com/question/10441359
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Answer:
A. Show that the total of the masses of the starting substances equals the mass of the mixture.
Explanation:
Law of conservation of mass:
According to the law of conservation mass, mass can neither be created nor destroyed in a chemical equation.
This law was given by French chemist Antoine Lavoisier in 1789. According to this law mass of reactant and mass of product must be equal, because masses are not created or destroyed in a chemical reaction.
For example:
In given photosynthesis reaction:
6CO₂ + 6H₂O + energy → C₆H₁₂O₆ + 6O₂
there are six carbon atoms, eighteen oxygen atoms and twelve hydrogen atoms on the both side of equation so this reaction followed the law of conservation of mass.
In a similar way if we have mixture of sugar and sand the total weight of mixture is equal to the weight of reactants.
sand + sugar + water → mixture
10g+5g+20 g = 35 g
