Answer:
A. Because they are compounds, they cannot be pure substances.
Explanation:
The false statement from the given choices is that because they are compounds they cannot be pure substances. In fact, because they are compounds they are pure substances.
Pure substances are made up of elements and compounds and they have the following properties:
- All parts are the same throughout
- Composition is definite
- They cannot easily be separated or broken
- Separation by physical method is not easy
- They have unique sets of physical and chemical properties.
Answer: λ = 635 ~6.36 × 10^ −7 m
Explanation:
We know that the mass number (top number) must be 33 because the electron that is emitted has no mass. The atomic number (bottom number) must be 15, because it is one less than 16 and the electron has a negative charge. Therefore, the first box is the answer.
