Answer:
D. release of carbon dioxide on heating limestone
The answer is D
Calcium has two electrons in its outer energy shell
<span>All molecules are made up of atoms.
N2 O2 and H2 exist in molecule form and not in atomic form.
They exist freely in nature as molecules.
According to above explanation,
</span><span>B. Some elements found in nature exist as molecules, is the correct answer.</span>
Answer:
The mass of glycerol that the student should weigh out depends on the volume that is needed. For example, the density of glycerol is 1.26 g/mL. Then, if 500 mL of glycerol is needed, 630 g should be weighed.
Explanation:
Density is the amount of mass per unit of volume. Density relates how many grams 1 milliliter of a substance weighs. Thus, if the density of glycerol is 1.26 g/mL means that 1.26 grams of glycerol occupy 1 mL of volume, or, in other words, 1 mL of glycerol weighs 1.26 grams.
Therefore, if 500 mL of glycerol is required to use for an experiment, 630 grams need to be weighed:
1 mL glycerol________ 1.26 g
500 mL glycerol______ x= 500mL * 1.26 g / 1 mL = 630 g
C I think not sure give it a try
