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:
The correct answer is b polar covalent
Explanation:
When two atoms joined by covalent bond has difference in their electronegativities at that time polarity arise.
When the electronegativity difference is low such as 1.3 then the polar bond formed by the two atoms are called polar covalent bond.For example H2O
on the other hand polar bond formed by two atoms having high difference in their electronegativities is called ionic bond.For example NaCl.
The Environmental Protection Agency suggests using cold tap water for cooking instead of starting with warm tap water is because our drinking water is made out lead pipes, which is a serious risk to health.
Explanation:
- Lead is found throughout the environment in lead found in paint, air, soil, food and water.
- Lead can pose a significant risk to your health if too much of it enters your body.
- Lead enters drinking water primarily as a result of the corrosion.
- It also contains in materials containing lead like in the water distribution system and household plumbing.
- Lead in drinking rarely cause of lead poisoning can significantly increase a person’s total lead exposure.
- In particular the exposure of infants who drink baby formulas and concentrated juices that are mixed with water.
- EPA estimates that drinking water can make up to 20% or more of a person’s total exposure to lead which is dangerous.
Answer:
A liquid has a definite volume but not a definite shape
