<span>a chemical change results in the formation of one or more new substances</span>
Answer : The correct option is D.
Explanation :
Balanced chemical equation : It is defined as the mass or component of each atom should be equal on both sides of the equation.
The balanced chemical equation for the reaction of 
and 
is,
So, the correct option is D.
Answer: As the temperature of the thermometer has increased it shows that that the reaction that has taken place was exothermic. In exothermic reactions heat is given out and temperature of the surroundings increases which is indicated by the increase in temperature of the thermometer.
Explanation:
<span>Rules for the Principal Energy Level. A principal energy level may contain up to 2n2 electrons, with n being the number of each level. The set of three p orbitals can hold up to 6 electrons. Thus, the second principal energy level can hold up to 8 electrons, 2 in the s orbital and 6 in the p orbital.</span>
To determine whether our equations are balanced, we must write the elements on the products side and also the reactants side. If the amount of the elements (coefficients and subscripts) are equal on both sides, we have a balanced equation.
Lets try (A)
2NaCl + H₂SO₄ → HCl + NaSO₄
Na=2 Na=1
Cl=2 Cl=1
H=2 H=1
Na=2 Na=1
S=1 S=1
O=4 O=4
Most of the elements here are not equal for both sides, therefore, A is not the answer.
Lets try (B)
2Na + S → 2NaS
Na=2 Na=2
S=1 S=2
This is a wrong answer because S is not equal on both sides. B is a wrong answer.
Lets try (C)
KOH + H2SO4 → KHSO4 + H2O
K=1 K=1
O= 1 O=1
H=1 H=1
H=2 H=2
S=1 S=1
O=4 O=4
THIS IS A BALANCED EQUATION!!!! ALL ELEMENTS ARE EQUAL ON BOTH SIDES!!!
Since we already know that C is our answer, we have no need to check D. Also, D is incorrect because N has 1 on reactants side, and 2 on the other. Therefore, we automatically know that D is wrong.
FINAL ANSWER: C IS OUR ANSWER, IT IS A BALANCED EQUATION. :)
