Answer:
Only two elements are liquid at standard conditions for temperature and pressure: mercury and bromine. Four more elements have melting points slightly above room temperature: francium, caesium, gallium and rubidium.
Explanation:
One molecule of glucose has 6 carbon atoms. So if you have three molecules of glucose, simply multiply 3 by 6 carbon atoms. The correct answer is C. 18 Carbon atoms.
The correct answer for the second questions is C. Air. A homogenous mixture is a mixture in which its components are uniformly distributed throughout the mixture. It has a sigle phase.
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.
