Answer:
a measure of how acidic/base water is.
Explanation:
hope it's helpful (◕ᴗ◕✿)
Answer:
A). Calcium chloride dihydrate (CaCl2 * 2H2O) slowly heated in a crucible to become calcium chloride (anhydrous).
Dehyration is a physical process
B). A hydrocarbon such as propane (C3H8) undergoes combustion to power a grill
Combustion is a chemical process.
C). A rock climber’s rope becomes frayed and turns the color of the rocks
This is physical process
D). A dog urinates on an air conditioner coil and the coil becomes corroded
Corrsion is a chemical process.
Explanation:
Answer:
The number of atoms in 20 grams of Pa-234 is 5.14 ×10²² atoms
Explanation:
Given that the molar mass of Pa-234 (protactinium) is 234.04331, we have
The number of moles of protactinium in 20 grams of Pa-234, we have
Number of moles = Mass/(Molar mass) = 20/234.04331 = 0.0855 moles
One mole of Pa-234 contains 6.02×10²³ atoms, therefore, we have;
0.0855 moles of Pa-234 contains 0.0855× 6.02×10²³ = 5.14 ×10²² atoms
Therefore, the number of atoms in 20 grams of Pa-234 = 5.14 ×10²² atoms.
