Answer:
Radiation
Explanation:
A sun transfers energy by radiation. However, there are three different modes of heat energy transfer -
a) Radiation
b) Conduction
c) Convection
Since sun is a at a very far distance from earth, it cannot transfer its heat energy by conduction as for this mode of heat transfer two bodies need to be in touch with each other.
For convection mode of heat transfer a medium is required but for transfer of sun's energy (which is electromagnetic radiation) no medium is required.
Hence, Sun will transfer energy by radiation only.
Hope This Helps!!! <3
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:
E = mct
Energy = (mass) x (specific heat capacity of water) x (change in temp)
585.24 = 53.2 x 4.2 x (X-24.15)
585.24 divided by 53.2 divided by 4.2 = X - 24.15
2.62 = X - 24.15
X= 26.77degrees C
(Specific heat capacity for water is 4.2 but is different for other liquids)
Yeah what the other person said ^