Which of the following are guidelines to follow for obtaining accurate observations? a. taking careful measurements b. using vague, boring language c. making careful sketches d. making up data to fill in gaps

The guidelines for making good and accurate observations are:

1. Standardise the experimental setup: Know the precision and the accuracy of the instrument used to make observations. Example, thermometer with a least count of 1°C cannot measure in fractional values.

2.Take careful measurements: Holding the instrument properly without causing any disturbance is the key.

answer: ice crystals in air

the water from the water body or another source of water gets evaporated as water vapor as an effect of heat on water. these water vapor rises in the upper layers of the earth atmosphere under high atmospheric pressure. the atmospheric pressure of these water molecules starts to decrease due to the effect of cold air. the invisible water vapor condenses into visible water droplets and ice crystals.these ice crystals and water droplets being less denser than the surrounding air floats on air as clouds.