Answer:
B
Explanation:
It's the same substance but in different states.
HETEROGENEOUS mixtures contain substances that are
not uniform in composition. The parts in the mixture can be separated by physical means.
Answer:
5.37 × 10⁻⁴ mol/L
Explanation:
<em>A chemist makes 660. mL of magnesium fluoride working solution by adding distilled water to 230. mL of a 0.00154 mol/L stock solution of magnesium fluoride in water. Calculate the concentration of the chemist's working solution. Round your answer to 3 significant digits.</em>
Step 1: Given data
- Initial concentration (C₁): 0.00154 mol/L
- Initial volume (V₁): 230. mL
- Final concentration (C₂): ?
- Final volume (V₂): 660. mL
Step 2: Calculate the concentration of the final solution
We want to prepare a dilute solution from a concentrated one. We can calculate the concentration of the final solution using the dilution rule.
C₁ × V₁ = C₂ × V₂
C₂ = C₁ × V₁ / V₂
C₂ = 0.00154 mol/L × 230. mL / 660. mL = 5.37 × 10⁻⁴ mol/L
Il fait plus chaud à l'équateur et plus froid aux pôles car : 1°) les rayons du Soleil sont plus concentrés au niveau de l'équateur et plus diffus au niveau des pôles ; 2°) l'épaisseur d'air composant l'atmosphère, traversée par les rayons du Soleil est plus importante aux pôles qu'à l'équateur.
Answer:
Mathematically, symmetry means that one shape becomes exactly like another when you move it in some way: turn, flip or slide. ... There are three basic types of symmetry: rotational symmetry, reflection symmetry, and point symmetry.
