Which particles are equal in number for an atom with a neutral charge? ​


Answer 1
Answer: electrons and protons

Related Questions

Exactly 1.5 g of a fuel burns under conditions of constant pressure and then again under conditions of constant volume. In measurement A the reaction produces 25.9 kJ of heat , and in measurement B the reaction produces 23.3 kJ of heat. Which measurement (A or B) corresponds to conditions of constant pressure? Which one corresponds to conditions of constant volume? Explain.
Consider the combination reaction of samarium metal and oxygen gas. If you start with 33.7 moles of samarium metal, how many moles of oxygen gas would be required to react completely with all of the samarium metal? For this reaction, samarium has a +3 oxidation state within the samarium/oxygen compound.
A piston confines 0.200 mol Ne(g) in 1.20 at 25 degree C. Two experiments are performed. (a) The gas is allowed to expand through an additional 1.20 L against a constant of 1.00atm. (b) The gas is allowed to expand reversibly and isothermally to the same final volume. Please calculate the work done by the gas system in these two processes, respectively. Which process does more work? (revised from 6/e exercise 8.11) Please show calculation details.
Which element has a complete valence electron shell?selenium (Se) oxygen (0) fluorine (F) argon (Ar) Mark this and return Viewers/AssessmentViewer/Activit Save and Exit Nexh Submit
Given the information about each pair of acids fill in the correct answer. a. Acid A has a lower % ionization than B:_______ is a stronger acid. b. Acid B has a larger K_a than acid A._______ will have a larger percent ionization. c. A is a stronger acid than B. Acid B will have________ percent ionization than A.

Determine the number of moles of oxygen atoms in each of the following.1) 4.93 mol H2O2
2) 2.01 mol N2O


Answer :

Part 1: 4.93 moles of H_2O_2 contains 9.86 moles of oxygen atoms.

Part 2: 2.01 moles of N_2O contains 2.01 moles of oxygen atoms.

Explanation :

Part 1: 4.93 mol H_2O_2

In 1 mole of H_2O_2, there are 2 atoms of hydrogen and 2 atoms of oxygen.

As, 1 mole of H_2O_2 contains 2 moles of oxygen atoms.

So, 4.93 moles of H_2O_2 contains 4.93* 2=9.86 moles of oxygen atoms.

Thus, 4.93 moles of H_2O_2 contains 9.86 moles of oxygen atoms.

Part 2: 2.01 mol N_2O

In 1 mole of N_2O, there are 2 atoms of nitrogen and 1 atom of oxygen.

As, 1 mole of N_2O contains 1 mole of oxygen atoms.

So, 2.01 moles of N_2O contains 2.01* 1=2.01 moles of oxygen atoms.

Thus, 2.01 moles of N_2O contains 2.01 moles of oxygen atoms.

the ionization constant for dichloroacetic acid HC2HO2Cl2 is 5.0 x 10^-2 . What is the pH of a 0.15 molar solution of this acid?


Answer: pH = 1.19


The formula for Ka is:  Ka = [H+][A-]/[HA]

where:  [H+] = concentration of H+ ions

[A-] = concentration of conjugate base ions

[HA] = concentration of undissociated acid molecules

Equation of reaction:  Cl₂CHCOOH ---> H+ + Cl₂CHCOO-

From the equation above, dichloroacetic acid dissociates one H+ ion for every Cl₂CHCOO- ion,

so [H+] = [Cl₂CHCOO-].

Let x represent the concentration of H+ that dissociates from HA, then [HA] = C - x where C is the initial concentration.

Substituting these values into the Ka equation:

Ka = x · x / (C -x)

Ka = x²/(C - x)

(C - x)Ka = x²

x² = CKa - Kax

x² + Kax - CKa = 0

Solve for x using the quadratic formula:

x = [-b ± √(b² - 4ac)]/2a

Note: There are two solutions for x. However only the positive value of x is used since x represents a concentration of ions in solution, and so cannot be negative.

x = [-Ka + √(Ka² + 4CKa)]/2

Substitute the values for Ka and C in the equation above:  

Ka = 5.0 x 10^-2

C = 0.15 M  

x = {-5.0 x 10^-2 + √[(5.0. x 10^-2)² + 4(0.15)(5.0 x 10^-2)]}/2

x = (-5.0 x 10^-2 + 1.80 x 10^-1)/2

x = 0.13/2

x = 6.50 x 10^-2

To find pH, we use the formula;

pH = -log[H+]

pH = -log(x)

pH = -log(6.50 x 10^-2)

pH = -(-1.19)

pH = 1.19

A 6.13 g sample of an unknown salt (MM = 116.82g/mol) is dissolved in 150.00 g water in a coffee cup
calorimeter. Before placing the sample in the water, the
temperature of the salt and water is 23.72°C. After the
salt has completely dissolved, the temperature of the
solution is 28.54°C.

If 3.15 x 10J of heat was gained by the solution, what
is the total heat for the dissolution reaction of the 6.13 g
of salt?


According to law of conservation of energy, if 31.5 J of heat is gained than same amount of heat is lost .

What is law of conservation of energy?

According to law of conservation of energy, it is evident that energy is neither created nor destroyed rather it is restored at the end of a chemical reaction .

Law of conservation of mass and energy are related as mass and energy are directly proportional which is indicated by the equation E=mc².Concept of conservation of mass is widely used in field of chemistry, fluid dynamics.

Law needs to be modified in accordance with laws of quantum mechanics under the principle of mass and energy equivalence.This law was proposed by Julius Robert Mayer in the year 1812.

Learn more about law of conservation of energy,here:




-3.19x10³ J


Since the surroundings absorbed 3.19 × 10³ J (or 3190 J) of heat, the system, or the dissolution reaction, must have lost the same amount of heat. The heat for the system, then, is -3.19 × 10³ J (or -3190 J). We know this is true because of the first law of thermodynamics, "heat is a form of energy, and thermodynamic processes are therefore subject to the principle of conservation of energy".

What is the concentration of a solution that has 15.0 g NaCl dissolved to a total of 750 ml?


Answer: The concentration of solution is 0.342 M


To calculate the molarity of solution, we use the equation:

\text{Molarity of the solution}=\frac{\text{Mass of solute}* 1000}{\text{Molar mass of solute}* \text{Volume of solution (in mL)}}

We are given:

Mass of solute (Sodium chloride) = 15 g

Molar mass of sodium chloride = 58.5 g/mol

Volume of solution = 750 mL

Putting values in above equation, we get:

\text{Molarity of solution}=(15g* 1000)/(58.5g/mol* 750mL)\n\n\text{Molarity of solution}=0.342M

Hence, the concentration of solution is 0.342 M

1. Thein an atom of that element.
number of an element equals the number of protons
2. The exact position of the electrons of an atom cannot be determined because they are
in constant
to the nucleus of an atom have the least
3. The electrons
amount of energy
4. The number of
bonds that atom can form.
in an atom tells you how many chemical



1. Proton = electron if the element is not in an ionic state

proton = atomic number

Testbank, Question 098 In the reaction between an alkyne and Na metal in liquid ammonia, the role of Na is as a(n) ___________.a. catalyst
b. electrophile
c. Brønsted base
d. reducing agent
e. Bronsted acid



d. reducing agent


Na acts as a  reducing agent. A reducing agent is a substance whose function is to reduce or donate electrons to another, and by doing so it becomes oxidized.  We can see the mechanism of the reaction in the image attached below.

Final answer:

In the chemical reaction between an alkyne and Na in liquid ammonia, Na acts as a reducing agent, donating electrons and facilitating the reduction of the alkyne to a trans-alkene.


In the reaction between an alkyne and Na metal in liquid ammonia, the role of Na is as a reducing agent. A reducing agent is a substance that donates electrons in a chemical reaction, facilitating the process of reduction. In this specific reaction, Na donates its outer shell electron to the alkyne, facilitating its reduction to a trans-alkene. Therefore, answer d. reducing agent is the correct choice among the given options.

Learn more about Reducing Agent here: