The testable question which will provide evidence that elements in the same group have similar properties is valency
<h3>What is the valency?</h3>
In essence, how many electrons are present in their outermost shell.
Valency and Groups in the periodic table, elements are arranged in order of their atomic numbers and hence, the periodic table is a systematic arrangement of elements in an array of vertical columns called Groups and horizontal arrays called Periods.
which of the following testable questions will provide evidence that elements in the same group have similar properties A. Valency B. Orbit C. Group D. Period
Since, the reactive capacities of elements is dependent on the number of electrons on its outermost shell, we can conclude on this note that, Elements in the same group have similar properties.
Learn more on Groups and Valency:
brainly.com/question/1645905
Answer:
option b is the correct answer
Answer:
42.65g
Explanation:
Given parameters:
Mass of K = 4g
Unknown: Mass of KCl
Solution:
Complete equation of the reaction:
2K + Cl₂ → 2KCl
To solve this problem, we know that the reactant in short supply is potassium K and this dictates the amount of products that would be formed. The chlorine gas is in excess and we can't use it to determine the amount of product that would form.
Now, we work from the known to the unknown. Since we know the mass of K given in the reaction, we can simply find the molar relationship between the reacting potassium and the product. We simply convert the mass to mole and compare to the product. From there we can find the mass of KCl that would be produced.
Calculating number of moles of K
Number of moles = 
Number of moles of K = 
= 0.103mol
From the given reaction equation:
2 moles of K will produce 2 moles of KCl
Therefore 0.103mol of K will produce 0.103mol of KCl
To find the mass of KCl produced,
Mass of KCl = number of moles of KCl x molar mass
Molar mass of KCl = 39 + 35.5 = 74.5gmol⁻¹
Mass of KCl = 0.103 x 74.5 = 42.65g
<h2>Answer : Option B) Hydrogen</h2><h3>Explanation :</h3>
All fossil fuels contains hydrocarbons in it. Amongst the given options hydrogen is the correct answer. Except that it contains carbon in it. Hydrocarbons are those class of compounds which contains hydrogen and carbon as element in it.
They are considered to be good fuels because they naturally bring out complete combustion as they contain hydrogen and carbon in its compound form.
Molar solubility is number of moles of the solute that can be dissolved per liter of solution before the solution becomes saturated.
The molar solubility of lead(ii) chloride with ksp value of 2.4 × 10e4 can be solve as:
Ksp = s2 = 2.4 × 10e4
s2 = 2.4 × 10e4
s = √(2.4 × 10e4)
s = 154.9 mol/L
