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
Aluminum has a chemical formula of Al, while diatomic bromine has a chemical formula of Br₂. The balanced chemical reaction is shown below:
<em>2 Al (s) + 3 Br₂ (l) → 2 AlBr₃ (s)</em>
The solid product is called Dibromoaluminum. The stoichiometric coefficients are used to balance the reaction to obey the Law of Conservation of Mass.
Answer:
I believe Na
Explanation:
Copper, because it is the only metal out of all of them.
Therefore copper is the only element that can loose electrons to have a positive charge, it is the most likely to become a cation.
Answer:
This work was done in the European plum (Prunus domestica). The gene for PPV coat protein was separated from the PPV virus and inserted into the plum DNA, which was then regenerated and grown into complete plum trees. These trees now had the additional gene in their DNA and became resistant to PPV.
