A student places a 12-gram cube of ice inside a container. After six hours, the student returns to observe the contents of the container. Which sentence suggests that the container is an open system? A. 

The container contains 12 grams of liquid water and no ice.

B. 

The container contains 12 grams of ice and no liquid water.

C. 

The container contains 8 grams of liquid water and no ice.

D. 

The container contains 8 grams of ice and 4 grams of liquid water.

E. 

The container contains 8 grams of liquid water and 4 grams of water vapor.

The answer is c

Explanation:

Because all of the Other ones did not make sense

it should be p1 v1 = p2 v2

- calcium has greater affinity to bond with electron receptors than hydrogen does and hence, it has the ability to replace hydrogen in most of its compounds.

- lithium has 2 valence electrons in the product because it can make only 1 bond with hydrogen. beryllium has 4 valence electrons in the product because it can only make 2 bonds. it has fewer electrons than neon and can react with electron donors. each hydrogen has 2 valence electrons, the same as helium.

- the covalent bond formed between carbon and hydrogen is polar because carbon is more electronegative than hydrogen and it attracts the bonded electron pair closer to itself, thus giving hydrogen a partial positive charge.

- a hydrogen bond is a relatively weak bond that hydrogen atoms make with the electronegative atoms nitrogen, oxygen or fluorine.

so the best choice is a.) 2 calcium (ca) atoms