Physical change- evaporation , condensation
Chemical change- combustion , neutralization
Dalton Found out there was a small, hard indestructible sphere that is the smalles part of an element.He created his own Atomic Theory:
-All Matter is made up of small particles called atoms.
-Atoms cannot be created, destroyed, or divided into smaller particles.
-All atoms of the same element are identical in mass and size. The atoms of one element are different in mass and size from the atoms of other elements.
<span>-Compounds are created when atoms of different elements link together in definite proportions.
</span><span>Rutherford had found the positively charged nucleus in the middle of every atom using his Gold Foil Experiment. While doing this experiment, he expected these particles to just pass right through the foil but they bounced right back. He also proposed there were negatively charged electrons revolving around the nucleus.
</span><span>Thompson found negative electrons and inferred atoms also contain negative particles. He inferred there was a lump of positively charged material, with negative electrons throughout. He used the Raisins Bun Model to explain.
</span>Chadwick <span>proved that it consisted of a neutral particle with about the same mass as a proton "Neutron" is the name given to the particle</span>
Bohr believed Rutherford's prediction was correct, but it wasn't complete. Bohr proposed electrons could only move between energy levels, rather then being able to move everywhere.
Answer:
- <u><em>butylphenyl ether.</em></u>
Explanation:
The formula of the compound is:
- CH₃ - CH₂ - CH₂ - CH₂ - O - C₆H₅
1. The functional group is of the kind R - O - R', i.e. two alkyl groups each attached to one end of the oxygen atom. That means that the compound is an ether.
2. One group attached to the oxygen group is CH₃ - CH₂ - CH₂ - CH₂ - which has 4 carbons and is named butyl group.
3. The other group attached to the oxygen atom is C₆H₅ - which is derived from ciclohexane as is known as phenyl group.
4. Using the rule of naming the subtituents in alphabetical order, you name butyl first and phenyl second, so it is <u><em>butylphenyl ether.</em></u>
The density of a material is the mass of the material per unit volume. Here the weight of the same metal is 44.40g, 40.58g and 38.35g having volume 4.8 mL, 4.7 mL and 4.2 mL respectively. Thus the density of the metal as per the given data are, 
= 9.25g/mL, 
= 8.634g/mL and 
= 9.130g/mL respectively.
The equation of the standard deviation is √{∑(x - 
)÷N}
Now the mean of the density is {(9.25 + 8.634 + 9.130)/3} = 9.004 g/mL.
The difference of the density of the 1st metal sample (9.25-9.004) = 0.246 g/mL. Squaring the value = 0.060.
The difference of the density of the 2nd metal sample (9.004-8.634) =0.37 g/mL. Squaring the value = 0.136.
The difference of the density of the 3rd metal sample (9.130-9.004) = 0.126 g/mL. Squaring the value 0.015.
The total value of the squared digits = (0.060 + 0.136 + 0.015) = 0.211. By dividing the digit by 3 we get, 0.070. The standard deviation will be 
. Thus the standard deviation of the density value is 0.265g/mL.
Answer:
+15.8°
Explanation:
The formula for the observed rotation (α) of an optically active sample is
α = [α]<em>lc
</em>
where
<em>l</em> = the cell path length in decimetres
<em>c</em> = the concentration in units of g/100 mL
[α] = the specific rotation in degrees
1. Convert the concentration to units of g/100 mL
2. Calculate the observed rotation
