Answer:
Dalton's atomic theory consisted of several postulates.
Explanation:
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All matter consists of indivisible particles called atoms.
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Atoms of the same element are similar in shape and mass, but differ from the atoms of other elements.
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Atoms cannot be created or destroyed.
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Atoms of different elements may combine with each other in a fixed, simple, whole number ratio to form compound atoms.
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Atoms of same element can combine in more than one ratio to form two or more compounds.
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Atoms are the smallest unit of matter that can take part in a chemical reaction.
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Answer:
A. percentage mass of iron = 5.17%
percentage mass of sand = 8.62%
percentage mass of water = 86.205%
B. (Iron + sand + water) -------> ( iron + sand) ------> sand
C. The step of separation of iron and sand
Explanation:
A. Percentage mass of the mixtures:
Total mass of mixture = (15.0 + 25.0 + 250.0) g =290.0 g
percentage mass of iron = 15/290 * 100% = 5.17%
percentage mass of sand = 25/290 * 100% = 8.62%
percentage mass of water = 250/290 * 100% = 86.205%
B. Flow chart of separation procedure
(Iron + sand + water) -------> separation by filtration using filter paper and funnel to remove water --------> ( iron + sand) -----------> separation using magnet to remove iron ------> sand
C. The step of separation of iron and sand by magnetization of iron will have the highest amount of error because during the process, some iron particles may not readily be attracted to the magnet as they may have become interlaced in-between sand grains. Also, some sand particle may also be attracted to the magnet as they are are borne on iron particles.
A controlled experiment is one in which evrerything is held constant except for one verieble, maybe is usually a st of data is taken for a control group.
Answer:
If the temperature increases the molecular movement as well, and if it increases the same it will happen with the molecular movement.
Pressure, volume and temperature are three factors that are closely related since they increase the temperature, the pressure usually decreases due to the dispersion of the molecules that can be generated, so the volume also increases.
If the temperature drops, the material becomes denser, its molecules do not collide with each other, their volume and pressure increases.
Explanation:
The pressure is related to the molecular density and the movement that these molecules have.
The movement is regulated by temperature, since if it increases, the friction and collision of the molecules also.
On the other hand, the higher the volume, the less pressure there will be on the molecules, since they are more dispersed among themselves.
(in the opposite case that the volume decreases, the pressure increases)
Answer:
148g/mol
Explanation:
The molar mass of a compound is the sum of the molar masses of all the individual elements present in the compound.
Molar Mass of Mg(NO3)2 = 24 + 2[14 + (16x3)] = 24 + 2[14 + 48] = 24 + 2[62] = 24 + 124 = 148g/mol