The answer to this question would be: 3.125%
Half-life is the time needed for a radioactive molecule to decay half of its mass. In this case, the strontium-89 is already gone past 5 half lives. Then, the percentage of the mass left after 5 half-lives should be:
100%*(1/2^5)= 100%/32=3..125%
Answer:
Both gives hydroxides, but
Calcium reacts with water to give calcium hydroxide Ca(OH)2. this product is slightly soluble in water.
Aluminium is less reactive than Ca, so it reacts with only steam, to give aluminium hydroxide Al(OH)3. This product is insoluble in water.
Answer:
co2
Explanation:
because carbon is a gas product
Answer: II. The catalyst provides a new pathway in the reaction mechanism.
III. The catalyst speeds up the reaction.
Explanation:
Activation energy is the extra energy that must be supplied to reactants in order to cross the energy barrier and thus convert to products.
A catalyst is a substance which increases the rate of a reaction by taking the reaction through a different path which involves lower activation energy and thus more molecules can cross the energy barrier and more molecules convert to products.
The catalyst itself does not take part in the chemical reaction and gets regenerated as such at the end of the reaction without getting consumed.
Hello!
As a chemical reaction occurs and the thermometer in the container records a decrease in temperature, the statement that is true about the reaction is: <span>The reaction is endothermic because heat was taken in by the reaction.
Endothermic reactions are those that require energy in the form of heat to be completed. Technically, in these reactions, the enthalpy of the products is higher than the enthalpy of the products. The requirement of energy causes the temperature to decrease. A general expression for an endothermic reaction can be written in the following way:
A + </span>Δ → B (Where Δ means heat)
Have a nice day!