A density of a substance is constant. It is an extensive property, meaning it does not depend on the amount of substance because it is a ratio of mass to volume. No matter how much of each there is, they would always have a fixed ratio called density. For lead, the density is
Density = mass/volume
Density = 23.94 g/ 2.10 cm³
Density = 11.4 g/cm³
Answer:
carbon dioxide
Explanation:
because we breath in oxygen and breath out Carbon
Answer: Options (a) and (d) are the correct answer.
Explanation:
A catalyst is the substance which helps in increasing the rate of reaction.
Activation energy is the minimum amount of energy required by reactants to start the reaction. On addition of catalyst, the path of reaction changes because the energy barrier gap reduces and hence, the activation energy also decreases.
In the absence of catalyst, we need to increase the temperature so that reaction can occur quickly.
Whereas on addition of catalyst, there is no need to increase the temperature as the catalyst itself is sufficient to increase the rate of reaction. As a result, temperature should be lowered when there is addition of catalyst in the reaction.
Thus, we can conclude that catalysts can save money by essentially lowering the activation energy and temperature required.
Answer:
increasing the number of molecules that have sufficient kinetic energy to react.
Explanation:
An increase in temperature affects the reaction rate by increasing the number of molecules that have sufficient kinetic energy to react.
or we say; temperature increase, leads to an increase in the amount of collisions between molecules.
