Which of the following statements is not true regarding physical properties and changes?

a. physical changes include evaporating, boiling, and dissolving.
b. physical changes can change compounds into elements.
c. physical properties can be observed without any change in the substance's identity.
d. a series of physical changes, such as filtration and heating, can be used to separate substances with different physical properties.

Iknow #2 is d. i just need to know why

The atomic radius of sodium is 186 pm and of chlorine is 100 pm. the ionic radius for na+ is 102 pm and for cl– is 181 pm. in going from na to cl in period 3, why does the atomic radius decrease while the ionic radius increases? a. the inner electrons in the sodium cation shield its valence electrons more effectively than the inner electrons in the chloride anion do. b. the inner electrons shield the valence electrons more effectively in the chlorine atom than in the chloride anion. c. the outermost electrons in chloride experience a smaller effective nuclear charge than those in the sodium cation do. d. the outermost electrons in chloride experience a larger effective nuclear charge than those in the sodium cation do. e. monatomic ions are bigger than the atoms from which they are formed.

The climate of the continental united states is generally 1. tropical 2. temperate 3. arctic 4. highland