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 cytoplasm slides and forms a pseudopodium in front to move the cell forwards.
I think the correct answer would be HCl + NaHCO3 -> NaCl + H2O + CO2, 2HCl + CaCO3 -> CaCl2 + CO2 + H2O, 2HCl + Mg(OH)2 -> MgCl2 + 2H2O. Hydrochloic acid would react with the basic substances in the stomach which are magnesium hydroxide, sodium bicarbonate and <span>calcium carbonate.</span>
Answer:
I think A it looks to be the answer
Explanation:
sorry if wrong
Answer:
Sodium (Na) has atomic number 11.
