A refracting telescope uses convex lenses to gather a large amount of light and focus it onto a small area while a reflecting telescope the mirror instead of an objective lens they are also similar because like the lenses in a refracting telescope the mirror in a reflecting telescope focuses a large amount of light onto a small area.
Answer:
Single replacement and Zinc Sulfate
the 2nd one is double replacement and potassium nitrate
Answer : It is a conclusion.
Explanation:
Conclusion: It is a judgement or decision which can be attained by reasoning.
From the observation table given we can conclude that :
- Aluminum ,bronze and steel took 27,45 and 80 seconds to melt small piece of wax respectively which means that more time will be required by them to transfer heat to the food while cooking. Hence, food will take more time to cook in them.
- Copper took less time of 15 seconds to melt the small piece of wax in comparison to other metal pots which means that it is a good conductor of heat in comparison to other. Hence, copper pot would be better for cooking food quickly.
After analyzing the observations and results in an experiment conclusion was made that copper pots are best for cooking foods.
Volume fraction = volume of the element / volume of the alloy
Volume = density * mass
Base: 100 grams of alloy
mass of tin = 15 grams
mass of lead = 85 grams
volume = mass / density
Volume of tin = 15g / 7.29 g/cm^3 = 2.06 cm^3
Volume of lead = 85 g / 11.27 g/cm^3 = 7.54 cm^3
Volume fraction of tin = 2.06 cm^3 / (2.06 cm^3 + 7.54 cm^3) = 0.215
Volume fraction of lead = 7.54 cm^3 / (2.06 cm^3 + 7.54 cm^3) = 0.785
As you can verify the sum of the two volume fractions equals 1: 0.215 + 0.785 = 1.000
Answer:
Br- Withdraws electrons inductively
Donates electrons by resonance
CH2CH3 - Donates electrons by hyperconjugation
NHCH3- Withdraws electrons inductively
Donates electrons by resonance
OCH3 - Withdraws electrons inductively
Donates electrons by resonance
+N(CH3)3 - Withdraws electrons inductively
Explanation:
A chemical moiety may withdraw or donate electrons by resonance or inductive effect.
Halogens are electronegative elements hence they withdraw electrons by inductive effect. However, they also contain lone pairs so the can donate electrons by resonance.
Alkyl groups donate electrons by hyperconjugation involving hydrogen atoms.
-NHCH3 and contain species that have lone pair of electrons which can be donated by resonance. Also, the nitrogen and oxygen atoms are very electron withdrawing making the carbon atom to have a -I inductive effect.
+N(CH3)3 have no lone pair and is strongly electron withdrawing by inductive effects.
