Answer: Mass of
produced in this reaction was 6.56 grams
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.

Mass or reactants = Mass of
+ mass of
= 16.00 + 64.80 = 80.80 g
Mass of products = mass of aqueous solution + mass of
+ = 74.24 + x g
Mass or reactants = Mass of products
80.80 g = 74.24 + x g
x = 6.56 g
Thus mass of
produced in this reaction was 6.56 grams
<u>Answer:</u> The force that must be applied is 15 N.
<u>Explanation:</u>
Force exerted on the object is defined as the product of mass of the object and the acceleration of the object.
Mathematically,

where,
F = force exerted = ?
m = mass of the object = 3 kg
a = acceleration of the object = 
Putting values in above equation, we get:

Hence, the force that must be applied is 15 N.
Electrons: negative
Protons: positive
Neutrons: nuetral
Answer:K2X
Explanation: Valency can be defined as the combining power of an element. It is the valency that dictates the value an element will have when writing a chemical formula for its compound.
MgX is a compound of magnesium and an element X. The valency of magnesium in most of its compound is +2. Now for the 2 to have been absent in the chemical formula, this shows that the element X itself have a valency if -2 for the valencies of both to have canceled out.
Now considering the element potassium, it is an alkaline metal belonging to group 1 of the periodic table. Hence, it is expected that it has a valency of +1
Forming a compound with element X means there would be an exchange of valencies between the two. We have established that x has a valency of -2. The formula of the compound thus formed by exchanging the valencies of both element would be K2X
I think the best answer is the last option. A scatter plot is the appropriate type of graph for the student to use to show the percent samples per group. This plot is somewhat similar to line graphs. However, they are use for a specific purpose which is to show the relationship between two parameters. In this case, the correlation between pH and the percent of samples.