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Are these answers in physical science correct? If not why?

Question by Kailee Marie does not like you >:): Are these answers in physical science correct? If not why?
1. Scientists today learn about the world by _____.

a.using untested hypotheses to revise theories
b.observing, measuring, testing, and explaining their ideas
c.formulating conclusions without testing them
d.changing scientific laws

My answer: B.observing, measuring, testing, and explaining their ideas.

2. The best base unit for measuring the length of a football field is a
a.dekameter
b.meter
c.centimeter
d.kilometer

My answer is: B. Meter

3.Following warnings, which one refers to a physical property of a substance?
a.fragile
b.flammable
c.reacts with water
d.explosive

My answer is: A. Fragile

4. Compound AICI^3 has how many atoms?
a.1
b.2
c.3
d.4
My answer is C.

5. The specific heat of aluminum is 0.125 cal/g ºC. If 12.5 grams of aluminum were heated from 20.0 ºC to 100.0 ºC, (100 or156or125) calories of heat energy would be absorbed by the aluminum.

My answer is: 100

6.The molecular weight of nitrous oxide, NO, is 30.006 a.m.u., and the molecular weight of carbon monoxide, CO, is 28.01 a.m.u. Thus NO diffuses (the same as or faster than or slower than) CO.

My answer is: Slower than

7.A 16.6 g sample of alcohol absorbs 890 Joules of energy as it is heated. If the initial temperature of the alcohol was 21.5 ºC, what is the final temperature of the ethanol?

a. 41 ºC
b.19.5ºC
c.43.2ºC

My answer is 41ºC

8.In an active solar system, a water or hydronic substance is heated in a solar collector. What is a hydronic substance?

a.propane
b.natural gas
c.a liquid-based substance
d.diesel

My answer is: C. A liquid-based substance

9.Lightening strikes cars and airplanes, but people are safe inside because _____.

a.the rubber tires insulate the car
b.the charge flows to the exterior of the car and is discharged
c.lightening is not attracted to metal
d.lightening is not attracted to people

My answer is: B. the charge flows to the exterior of the car and discharged.

10.Parallel circuits are most likely to be used in which of the following?

a.flashlight
b.holiday light strings
c.a calculator
d.a house

My answer is: House

11.Non-ferromagnetic materials tend to have (paired or valence or unpaired) electrons in each orbital.

My answer is: Valence

12. If you shout at a cliff wall that is 440 m away and the air temperature is at 25 ºC, how long will it take before you hear your echo?

My answer is: 1.27s

Best answer:

Answer by Rakesh
Answer of 4. will be D i.e 4

What do you think? Answer below!

This entry was posted on Wednesday, February 22nd, 2012 at 4:00 pm and is filed under Active Solar Heating. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

2 Responses to “Are these answers in physical science correct? If not why?”

  1. 11. Answer: Paired.
    The paired electrons in each orbital results in cancellation of spins, giving rise to non ferromagnetic behaviour.

  2. Madhukar Daftary on February 22nd, 2012 at 4:04 pm

    1, 2, 3 are correct.
    4 – d. 4 (Al is one atom and 3 atoms of chlorine make it 4)
    5. Heat reqd. = ms(t2 – t1) = (12.5)*(0.125)*(100-20) = 125 cals.
    6. correct
    7. The specific heat of ethanol is 2.46 J/goC.
    => 890 = 16.6 * 2.46 * (t – 21.5) => t = 43.3 => a. 41 degree is correct.
    8. correct.
    9, 10 correct.
    11. don’t know.
    12. double of your answer. You did not consider return path for echo to travel.

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