Question

Answering which question would best allow you to dig deeper into the content at the heart of the passage?

Why does a fresh water body, when cooled, start freezing from the surface downward?

Why does the behavior of fresh water cooling by convection change at 4°C?

Can the temperature of the air above a fresh water body be subzero at the end of summer?

Can ice form on the surface of fresh water if the lower layers are not frozen?

Answer 1

How Does Arctic Sea Ice
Form and Decay?
by Peter Wadhams (excerpt)

Consider a fresh water body being cooled from above, for instance a lake at the end of summer experiencing subzero air temperatures. As the water cools the density increases so the surface water sinks, to be replaced by warmer water from below, which is in its turn cooled. This creates a pattern of convection through which the whole water body gradually cools. When the temperature reaches 4°C, the lake reaches its maximum density. Further cooling results in the colder water becoming less dense and staying at the surface. This thin cold layer can then be rapidly cooled down to the freezing point [0°C], and ice can form on the surface even though the temperature of the underlying water may still be close to 4°C. Thus a lake can experience ice formation while considerable heat still remains in the deeper parts.

Answer 2

I think what they're asking is, "Which question wasn't answered in the passage?"

Answer 3

I think it's either the first one or the last one.

Answer 4

@KyanTheDoodle THANK YOU. That clears it up some more. @Slacker thanks! I appreciate it.

Answer 5

I'm not sure whether that's sarcasm or not, but whatever. Thanks yo.

Answer 6

@KyanTheDoodle it wasn't sarcasm. lol. I appreciate the help!

Answer 7

@KyanTheDoodle I still haven't answered it though lol

Answer 8

Lol. Okay. Good. Because no one shall use sarcasm towards me! Never!

Answer 9

Well I don't think it's A or B. "Why?" isn't usually a question that can be answered in Science.

Answer 10

@KyanTheDoodle I'm clueless. If I get this one wrong, I'll fail the quiz.

Answer 11

Oh sheep.

Answer 12

Honestly, I don't usually give out answers, but I'd say D. This passage doesn't mention much about fresh water, if at all.

Answer 13

@KyanTheDoodle okay thank you. You did help though! thanks.

Answer 14

@KyanTheDoodle D wasn't correct :(((((

Answer 15

@paki can you help?