A quantitative observation must be a measurement of some sort. (Something including numbers). Qualitative, on the other hand, is when you are using words to describe what has happened.
The answer is 3). This is because elements are the simplest form of a substance, and cannot be broken down any further. Compounds on the other hand are much more complex than elements and can be broken down INTO elements.
For example, Na, sodium, is an element and cannot be broken down further. H2O, water, is a compound and can be broken down into Hydrogen and Oxygen.
Answer:
PF3 has a trigonal pyramidal molecular geometry.
Explanation:
PF3 has four regions of electron density / electron clouds around the central P atom. The regions of electrons make a tetrahedral arrangement with a bond angle of 109.5°. Only three regions of electrons are bonding and one is non-bonding, so the overall shape is trigonal pyramidal.
This is because air is trapped inside the car and it heats up to the same temperature of the car. Think of the car as a greenhouse.