Answer:
2
Explanation:
1 is definitely wrong
density must be lower to atop another liquid
in 3 ,I consider the example of water and oil whi has a lower boiling point
when sodium metal is dropped in water, hydrogen gas in liberated due to extreme heat released as the reaction is exothermic, gas catches fire.
Explanation:
Elements that belong to same group contains same number of valence electrons. Hence, they tend to show similar chemical properties.
When we move across a period then number of electrons get added to the same shell. As a result, there will be no increase in size of elements.
Also, metals are the elements that belong to group 1, 2 and d-block elements are also known as metals. Metallic character of elements decreases when we move left to right in a periodic table.
As most reactive metals are placed on the left side of periodic table.
Since, size of elements increases on moving down the group. So, an element is able to easily lose its valence electrons because of less force of attraction between its nucleus and valence electrons.
As a result, there will be increase in reactivity of metals on moving down the group.
Thus, we can conclude that given sentences are as follows.
- Elements in the same group have the same number of valence electrons.
-
Elements in the same period have the same number of electron shells.
-
Metallic elements become less reactive as you move left to right in a period.
-
Metallic elements become more reactive as you move top to bottom in a group.
We know that Weighted atomic mass of Element is Calculated based upon their existence of isotopes and the Relative abundance of these isotopes.
Given that the Element X is Composed of :
Isotope Relative abundance Atomic Mass
⁵⁵X 70% 55
⁵⁶X 20% 56
⁵⁷X 10% 57
Weighted Atomic Mass of Element X :
= (0.70)(55) + (0.20)(56) + (0.10)(57)
= 38.50 + 11.2 + 5.70
= 55.4
So, the Weighted Atomic Mass of Element X is 55.4
Answer:
3 H1 NMR signals
Explanation:
NB: kindly check the diagram of the chemical compound in the attached picture.
This particular Question is based on the part of chemistry which is known as spectroscopy. Spectroscopy is used in the Determination or in identifying chemical compounds. H'NMR works on the principle of nuclear magnetic resonance.
In order to solve this question, one has to count the number of hydrogen in unique location. The diagram in the attached show how hydrogen is been counted.
The numbers of signals is the number of different chemical environments in which hydrogen atoms are located.
NB: signals is also the same as peak in H'NMR.
Hence, the number of H1 NMR signals in this chemical compound is 3.
