Answer:
6 electrons.
Explanation:
An atom of oxygen has six electrons in its outermost energy level, and these are called valence electrons.
The question is typed wrong. Assuming the correct question is
How many liters of 0.98 M H2SO4 solution would react completely with 3.5 moles Ca(OH)2 ?
Answer:-
3.571 litres
Explanation:-
The balanced chemical equation for this reaction is
H2SO4 + Ca(OH)2 = CaSO4 + 2 H2O
From the balanced chemical equation we see that
1 mole of Ca(OH)2 reacts with 1 mol of H2SO4.
∴3.5 moles of Ca(OH)2 reacts with 1 x 3.5 / 1 = 3.5 mol of H2SO4.
Strength of H2SO4 = 0.98 M
Volume of H2SO4 required = Number of moles of H2SO4 / Strength of H2SO4
= 3.5 moles / 0.98 M
= 3.571 litre
Answer:
C. I, III , IV
Explanation:
As we move from left to right across the periodic table the number of valance electrons in an atom increase. The atomic size tend to decrease in same period of periodic table because the electrons are added with in the same shell. When the electron are added, at the same time protons are also added in the nucleus. The positive charge is going to increase and this charge is greater in effect than the charge of electrons. This effect lead to the greater nuclear attraction. The electrons are pull towards the nucleus and valance shell get closer to the nucleus. As a result of this greater nuclear attraction atomic radius decreases and ionization energy increases because it is very difficult to remove the electron from atom and more energy is required.
As we move down the group atomic radii increased with increase of atomic number. The addition of electron in next level cause the atomic radii to increased. The hold of nucleus on valance shell become weaker because of shielding of electrons thus size of atom increased.
As the size of atom increases the ionization energy from top to bottom also decreases because it becomes easier to remove the electron because of less nuclear attraction and as more electrons are added the outer electrons becomes more shielded and away from nucleus.
Answer:
B. it is a community of plants,animals and there physical surrounding.
The reaction as shown is known to be an exothermic reaction.
<h2>Endothermic and exothermic reaction:</h2>
Depending on the temperature of the reaction vessel after reaction, the reaction could be classified as;
In an endothermic reaction, heat is absorbed and the rate of reaction increasing with increase in temperature while in an exothermic reaction, the rate of reaction decreases with increase in temperature.
Hence, the correct statements are;
- The reaction is an exothermic reaction.
- The value of K decreases as the value of T increases.
Learn more about exothermic reaction: brainly.com/question/14969584
