Answer:
9.1 = basic 1.2= very acidic 5.7= acidic
Explanation:
It's where chemical elements are organized based on atomic weight. Also, like/similar physical and chemical properties in each interval of 7 elements.
It was a silly reason it was rejected. It was rejected because it's octaves were too similar to those in music.
I hope this helps!
4. A
because PbCl2 is an ionic compound and it's solid, so it's a substance.
It cannot be mixture, because it's a pure molecule.
5. D
despite that both substances are gases, colorless they are different molecules, so they should have different either chemical and physical properties
6. C
this substance made from W atoms and others are made from molecules