Answer: currency
Explanation:
B. muscular endurance.
C. cardiovascular endurance.
D. power.
Answer is: 4) form an aqueous solution.
Physical property can be observed and measured without any changes in molecular composition. The same substance is present before and after the change. Making aqueous solution is physical change (solvatation).
Element reactions with acids, oxygen and chlorine are chemical change (chemical reaction combustion), because new substances are formed, the atoms are rearranged and the reaction is followed by an energy change (exothermic reaction because energy is released).
Answer:
Different ions of different elements (usually metals) make a flame burn with a characteristic color when introduced into the reaction zone; the different colors are caused by the different quantized energy levels of the electrons in the different atoms.