Helium only possesses two valence electrons, while the other noble gasses posses eight
Answer:
The answer to your question is: letter A
Explanation:
a) A + B ⇒ AB + heat It is an exothermic reaction because heat is released.
b) A + BΔ ⇒ AB It heat added to the reactants , then it is an endothermic reaction.
c) heat + BC ⇒ B + C It's an endothermic reaction because heat is added to the reactants.
d) B + heat + CD ⇒ BD + C It's and endothermic reaction because heat is added to the reactants.
Answer:
The temperature, however, greatly affects the rate of a chemical reaction. As you heat a substance, its molecules move faster and are more likely to react. Some reactants even require some heat to initiate a reaction. Reaction Rates and Temperature
Explanation:
Answer:
Removing the dirty water and replacing with fresh water. also the fish containing in the aquarium change the system of aquarium.
<span>When one talks about ppm in a liquid solution someone means mg/L so we would not be using the density. This usually means ug/g or mg/kg
0.115 g Na^+ * 10^6 ug/1 g = 115000 ug/g
4.55 L * 1000 mL/1L = 4550 mL
Concentration of Na^+ in ppm:
115000 ug/g /4550 mL = 25.27 pm of sodium ion</span>
