4. The chart shows melting and boiling points of different substances.

Melting and Boiling Points

Substance

Alcohol

Formaldehyde

Nicotine

Benzene

Nitroglycerine

Melting Point ("C) Boiling Point ("C)

-114

78.2

-92

-19

-79

247

5.5

80

13.5

250

Which substance freezes at the lowest

temperature?

A. Alcohol

B. Nicotine

C. Formaldehyde

The correct option is A

Explanation:

Firstly, it should be noted that the freezing point of a substance can be assumed to be melting point of that substance because a substance will normally change from liquid to solid (freezes) at the same point it changes from solid to liquid (melts). For example, water freezes at 0°C and also starts melting at 0°C.

Thus, the substance with the lowest melting point among the substances mentioned in the question is alcohol (ethanol) with the melting point of -114°C. Hence, ethanol also has the lowest freezing point thereby freezing at the lowest temperature.

weather forecasts are done by collecting data about the current state of the atmosphere mainly the temperature, humidity and wind and using meteorology, to determine the atmosphere that evolves over time. the h and l mean the high and low pressure. the red strip is a warm front. the blue strip is a cold front. the blue and red strip is a stationary front. the purple strip is a occluded front.

explanation:

f=ma newton

f=100x2.5=250n