SAMPLE A - <span>pure substance.
</span>SAMPLE B - <span>homogeneous mixture.
</span>SAMPLE C - <span>heterogeneous mixture.
</span>Pure substance - <span>constant composition and properties.</span>
Homogeneous mixture - same uniform appearance and composition.
Heterogeneous mixture - <span>not </span>uniform<span> in composition, two phases (liquid and dust).
</span>
Answer:
2. Na2O
Reasoning:
Na (soduim) is the only metal out of all the elements in the answer choices, and is bonded with oxygen, a nonmetal, therefore creating an ionic bond.
This is false. The amount of electrons in lithium (Li) is not 7, it is 3. There are 3 electrons in lithium.
Explanation:
The given data is as follows.
, 
Area of the flat plate is 2 × 4 = 8
.
Average convection heat transfer coefficient
=
=
.
Hence, formula to calculate heat transfer through convection from air to the water is given as follows.
q = 
=
= 24000 W
or, = 24 kW
Hence, the direction of heat flow is from air to the surface.
Thus, we can conclude that transfer of heat is 24 kW.