The general form of a compound can be written in the form
of:
[X(a) Y(b)] ^ c
Where a and b are subscripts, and c is the superscript of
the whole formula.
The relationship that we can derived here between the
constants is:
(valence of X) * a + (valence of Y) * b = c
Since the formula obviously has no superscript, therefore
c = 0. We also know in chemistry class that the valence of Cl is -1, therefore:
valence of X * 1 + (-1) * 3 = 0
valence of X - 3 = 0
<span>valence of X = 3</span>
Answer
B. One element takes the place of another in a compound
Explanation
A single-replacement reaction occurs when one element is substituted for another element in a compound.The reacting materials are normally pure elements such as a metal or hydrogen gas with an aqueous compound.A new aqueous compound plus a different pure element are formed as products.
<span><span>KaAcid</span><span><span>1.0 * 109</span>Hydrobromic acidHBr</span><span><span>1.3 * 106</span>Hydrochloric acidHCl</span><span><span>1.0 * 103</span>Sulfuric acid<span>H2SO4</span></span><span><span>2.4 * 101</span>Nitric acid<span>HNO<span>3</span></span></span></span>
I found another question like this. Someone answered "The best answer to this question is adding a catalyst.
Adding a catalyst will cause the greatest increase in the rate of reaction for this chemical reaction , 8Zn(s) + S8(s) 8ZnS(s). ---> adding a catalyst always affects the rate of a reaction."
An atom that has 13 protons and 15 neutrons is isotope of Aluminium (answer C)
<u><em>Explanation</em></u>
- Isotope is a form of the same element with the equal number of protons but difference number of neutrons in their nuclei.
- In other words isotope has the same atomic number but different mass number.
- Atomic number of a element is determined by number of protons of an element.
- from the periodic table Aluminum in atomic number 13 therefore it has 13 protons <em>therefore an atom that has 13 protons and 15 neutrons is a isotope of Aluminium. </em>
