Answer:
the answer is A because the rest wouldnt go good with the work
Explanation:
It should be 24.2624 because if there’s 2.72g in every cm3 and there are 8.92 cm3, then you simply multiply the two numbers
hope this helped :)
= 6.42 × 10²²
(scientific notation)
= 6.42e22
(scientific e notation)
= 64.2 × 10²¹
(engineering notation)
(sextillion; prefix zetta- (Z))
= 64200000000000000000000
(real number)
Answer:
- Question 19: the three are molecular compounds.
Explanation:
<em>Question 19.</em>
All of them are the combination of two kinds of different atoms in fixed proportions.
- C₂H₄: two carbon atoms per four hydrogen atoms
- HF: one hydrogen atom per one fluorine atom
- H₂O₂: two hydrogen atoms per two oxygent atoms
Thus, they all meet the definition of compund: a pure substance formed by two or more different elements with a definite composition.
Molecular compounds are formed by covalent bonds and ionic compounds are formed by ionic bonds.
Two non-metal elements, like H-F, C - C, C - H, H-O, H - H, and O - O will share electrons forming covalent bonds to complete their valence shell. Thus, the three compounds are molecular and not ionic.
<em>Question 20. </em>Formula of copper(II) sulfate hydrate with 36.0% water.
Copper(II) sulfate is CuSO₄. Its molar mass is 159.609g/mol
Water is H₂O. Its molar mass is 18.015g/mol
Calling x the number of water molecules in the hydrate, the percentage of water is:

From which we can solve for x:

Thus, there are 5 molecules of water per each unit of CuSO₄, and the formula is:
Answer:
2g
Explanation:
2 half-lives will pass. Therefore the amount will be quartered into 2g.