Salutations!
What causes a substance to change states of matter?
Energy causes a substance to change states of matter. A matter needs energy to melt, evaporate, boil. Remember: Energy has a sudden change, but the temperature remains absolutely the same. An example of a change in energy is when ice is melting.
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Answer:
See explanation
Explanation:
Molar mass is obtained as the sum of relative atomic masses as follow;
For CaBr = 40.08 + 79.90 = 119.98 g/mol
For BeBr = 9.012 + 79.90 = 88.912 g/mol
For CdBr2 = 112.41 + 2(79.90) = 272.21 g/mol
For CuBr2 = 63.55 + 2(79.90) = 223.35 g/mol
Answer:
The correct answer is V1/T1=V2/T2.
Explanation:
Just took the test
Answer:
Option A.
2Na + 2H2O —> 2NaOH + H2
Explanation:
To know which option is correct, we shall do a head count of the number of atoms present on both side to see which of them is balanced. This is illustrated below below:
For Option A:
2Na + 2H2O —> 2NaOH + H2
Reactant >>>>>>> Product
2 Na >>>>>>>>>>> 2 Na
4 H >>>>>>>>>>>> 4 H
2 O >>>>>>>>>>>> 2 O
Thus, the above equation is balanced.
For Option B:
2Na + 2H2O —> NaOH + H2
Reactant >>>>>>> Product
2 Na >>>>>>>>>>> 1 Na
4 H >>>>>>>>>>>> 3 H
2 O >>>>>>>>>>>> 1 O
Thus, the above equation is not balanced.
For Option C:
2Na + H2O —> 2NaOH + H2
Reactant >>>>>>> Product
2 Na >>>>>>>>>>> 2 Na
2 H >>>>>>>>>>>> 4 H
1 O >>>>>>>>>>>> 2 O
Thus, the above equation is not balanced.
For Option D:
Na + 2H2O —> NaOH + 2H2
Reactant >>>>>>> Product
1 Na >>>>>>>>>>> 1 Na
4 H >>>>>>>>>>>> 5 H
2 O >>>>>>>>>>>> 1 O
Thus, the above equation is not balanced.
From the illustrations made above, only option A is balanced.
When you put a popcorn kernel in a microwave, the microwave heats up the water. The water then evaporates, and the air wants to escape. There will be so much pressure that the skin/shell of the kernel will break, exposing the corn.
