Answer:
The correct option is B
Explanation:
The number of valence electron(s) increases across the period and thus influences the direction of periodic trend of electronegativity, electron affinity and ionization energy across the period. Thus, making option B the answer.
It should be noted that option A is wrong because elements in the same period generally have the same number of electron shells and thus the distance of this shells from the nucleus remains the same throughout the same period and thus option C is also wrong. Option D is wrong because the periodic trends have to do with chemical reactions which actually involves electrons and not protons.
Answer: C) Elements and pure compounds are homogeneous materials because they have a uniform composition throughout.
Explanation: Element is a pure substance which is composed of atoms of similar elements. Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.
Elements are compounds form homogeneous materials as they have uniform composition throughout and the components are evenly distributed throughout the material.
Mixtures are heterogeneous materials as they do not have uniform composition and the components are not evenly distributed throughout the material.
Answer:
Specific heat is defined by the amount of heat needed to raise the temperature of 1 gram of a substance 1 degree Celsius (°C). Water has a high specific heat capacity which we'll refer to as simply "heat capacity", meaning it takes more energy to increase the temperature of water compared to other substances.
Explanation:
Answer: The statement collisions only result in a reaction if the particles collide with a certain maximum energy called the activation energy of the reaction, is false.
Explanation:
Activation energy is the minimum amount of energy required to initiate a chemical reaction.
So, when activation energy for a reaction is lower then molecules with lower energy can also participate in the reaction. As a result, more number of collisions will take place due to which an increase in the rate of reaction will takes place.
When activation energy for a reaction is larger then molecules with higher energy will not be able to participate in the reaction. As a result, less number of collisions will take place due to which a decrease in rate of reaction will occur.
Therefore, we can conclude that the statement collisions only result in a reaction if the particles collide with a certain maximum energy called the activation energy of the reaction, is false.
