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
Answer:
D.HI
Explanation:
because this is the most different
B. inference because she drew a conclusion based on evidence.
Because the evidence was that she heard the crashing sound, and then when she came into her room saw the broken window and baseball.
It was not an observation because she did not directly see the baseball going through the window
It is important because if the sample size is smaller, outliers could skew the data more than if it was large.
If the object has an irregular shape, the volume can be measured using a displacement can. The displacement can is filled with water above a narrow spout and allowed to drain until the water is level with the tap. As the irregular object is lowered into the displacement can, the water level rises.