Answer:
1. start line drawn in ink
2. start line below solvent level
Explanation:
1. the line would run up the paper. should have drawn with pencil.
2. the samples would dissolve into solvent and not run up the paper.
polyethylene contains HC=CH units.
mass of this is 26 gram/mol
number of such units =13500/26
By definition, one mole (one gram molecular weight) of any substance, contains Avogadro’s number of particles; atoms if you are discussing an element, or molecules if a compound. Avogadro’s number has been determined by several methods, all of the accepted values lie within a range of +-1% about the value of 6.022045 x 10^23/gm. That is a large number, in this case approximately; 602,204,500,000,000,000,000,000 molecules of glucose.
From the web :v
Answer:
6. 7870 kg/m³ (3 s.f.)
7. 33.4 g (3 s.f.)
8. 12600 kg/m³ (3 s.f.)
Explanation:
6. The SI unit for density is kg/m³. Thus convert the mass to Kg and volume to m³ first.
1 kg= 1000g
1m³= 1 ×10⁶ cm³
Mass of iron bar
= 64.2g
= 64.2 ÷1000 kg
= 0.0642 kg
Volume of iron bar
= 8.16 cm³
= 8.16 ÷ 10⁶


Density of iron bar

= 7870 kg/m³ (3 s.f.)
7.

Mass
= 1.16 ×28.8
= 33.408 g
= 33.4 g (3 s.f.)
8. Volume of brick
= 12 cm³

Mass of brick
= 151 g
= 151 ÷ 1000 kg
= 0.151 kg
Density of brick
= mass ÷ volume

(3 s.f.)
Answer: -
1) 8.33 minutes
2) 118.39 in/ s
180.43 m/min
10.83 km/ hr
Explanation: -
Speed of light = 3 x 10⁸ m/s
Distance of the earth from the sun= 93 million miles
We know 1 million = 1,000,000
Also 1 mile = 1609 m
Distance of the earth from the sun= 93 million miles
= 93,000,000 miles.
= 1.5 x
m
Time taken = 
=
m}{3 x 10⁸ m/s} [/tex]
= 500 s
= 500/ 60
= 8.33 minutes
2) Distance = 1 mile = 63360 inches
Time taken = 8.92 min
= 8.92 x 60
= 535.2 s
Speed = 
= 
= 118.39 in/ s
Distance = 1 mile = 63360 inches = 63360 x 2.54 cm = 63360 x 2.54 x
m
Time taken = 8.92 min
Speed = 
=
m}{8.92 min} [/tex]
= 180.43 m/ min
1 m = 10⁻³ Km
1 min = 1/60 hour
1 m /min = 10⁻³ km/ 
= 60/1000
=0.06 km/hr
180.43 m / min = 180 x 0.06 km / hr
= 10.93 km / hr