Select the correct locations on the periodic table.
which two elements have similar characteristics?

Explanation:

It is known that atoms that have same number of valence electrons will show similar chemical properties.

So, when we move from left to right across a period there occurs increase in number of valence electrons of each element. But when we move down a group then number of valence electrons remain the same.

Hence, elements of same group will show similar chemical properties.

Therefore, we can conclude that elements marked as 2 and 3 will have similar chemical properties.

Answer : The correct location on the periodic table of two elements have similar characteristics is, two elements present in the second column of the left side

Explanation :

The elements have similar characteristics when they are belong to the same family or group this means that when they are placed in the same column of the periodic table.

The elements of similar characteristics have same number of valence electrons.

In the given periodic table of the elements, the two elements present in the second column of the left side have similar characteristics because these two elements belong to the same family or group. While the other elements have different characteristics.

the equation that correctly represent the reaction for formation of ammonia is

n2+ 3h2 → 2nh3 (answer d)

1 mole of nitrogen gas (n2) react with 3 moles of hydrogen gas (h2) to form 2 moles of ammonia ( nh3). this is in a process known as haber process were iron is used as a catalyst and reaction take place that a higher temperature and pressure. the process is exothermic hence energy is released.

answer: enthalpy

explanation:

for a exothermic reaction, the energy is released i.e. the energy of the products is lower than the energy of the reactants.

= enthaply

= energy of products

= energy of reactants

as , thus comes out to be negative. negative value of enthalpy shows that the reaction is exothermic.