Answer:
Difference between Homogeneous mixture and Heterogeneous Mixture are as follows:
- A mixture or sample that is consist of uniform composition and properties is called a homogeneous mixture while a mixture or sample that is consist of different composition and properties is called a heterogeneous mixture.
- Homogenous mixture has only single phase while heterogeneous mixture has two or more phases.
- Homogenous mixture can not be separated by physical methods while heterogeneous mixture can be separated out physically.
- Example of homogenous mixture is Water and sugar and heterogeneous mixture is oil and water.
Answer:
0.19 g
Explanation:
Step 1: Given data
Volume of hydrogen at standard temperature and pressure (STP): 2.1 L
Step 2: Calculate the moles corresponding to 2.1 L of hydrogen at STP
At STP (273.15 K and 1 atm), 1 mole of hydrogen has a volume of 22.4 L if we treat it as an ideal gas.
2.1 L × 1 mol/22.4 L = 0.094 mol
Step 3: Calculate the mass corresponding to 0.094 moles of hydrogen
The molar mass of hydrogen is 2.02 g/mol.
0.094 mol × 2.02 g/mol = 0.19 g
Answer:
D
Explanation:
If the atom is neutral, the sum of the core and valence electrons is the same as the number of protons, which is the atomic number of the element. So if the sum of the core and valence electrons in a neutral atom equals 25 , that is the number of protons in the atomic nucleus, and the atomic number of the element.
