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
The answer you're looking for is: a wave.
The patient needs 1000 ml of 5% (w/v) glucose solution
i.e 1000 ml x 5 g/ 100 ml
where the stock solution is 55% (w/v) = 55 g / 100 ml
So, 1000 ml x 5 g / 100 ml = V (ml) x 55 g / 100 ml
V = 1000 x (5 / 100) / (55 / 100) = 5000 / 55 = 90.9 ml
∴ the patient needs 90.9 ml of 55% (w/v) glucose solution
Al2O3 has a higher melting point than Na2O. This is because the ionic bond between Al3+ ions and O2- ions is stronger than that between Na+ and O2-. The charge on the Al3+ ion is larger than that of the Na+ ion
The answer would be KMnO4, please let me know if you would like me to explain how i got this
