<span>A compound is ''composed'' of elements. The periodic table is made up of elements. Atoms makes up elements and elements when reacted together make compounds.
Na+ and Cl- makes NACL....salt. a compound</span>
The answer is number 4 or the exchange of energy with the surroundings. Calorimetry is a measurement of energy that is formed or absorbed in a certain process. The calorimeter is the instrument used in order to measure the energy. It is recommended that a calorimeter should be a closed system so as to measure precisely the energy and avoid or lessen the exchange of energy with the surroundings. Thus, comparing an open ceramic mug and an insulated mug with a lid, the greatest difference is the energy lost to the surroundings.
675 nanograms is equivalent to 6.75 × 10-⁴ milligrams.
<h3>How to convert nanograms to milligrams?</h3>
Nanograms is a unit of mass equal to 0.000000001 grams and has a symbol of ng.
On the other hand, milligrams is another unit of mass equal to 0.001grams and has a symbol of mg.
Nanograms and milligrams are both units of mass and can be inter-convertible as follows:
1 nanogram = 1 × 10-⁶ milligram
According to this question, 675 nanograms is equivalent to 675 × 10-⁶ milligrams.
Therefore, 675 nanograms is equivalent to 6.75 × 10-⁴ milligrams.
Learn more about milligrams at: brainly.com/question/20320382
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Answer:
carbondioxide is an example of compound.
