In which chemical equation is the number of atoms in the reactants the same as the number of atoms in the products?(1 point)
A) Zn + 2HCl → H2 + ZnCl2

B) CH4 + O2 → CO2 + 2H2O

C) Li2CO3 → LiO + CO2

D) CO2 + H2O → CH2OH + O2

2. Which statement is true regarding a chemical reaction?(1 point)

A) Even if the total number of atoms does not change, mass may not be conserved in the reaction.

B) Even if the total number of atoms changes, mass may not be conserved in the reaction.

C) The total number of atoms changes, so mass is conserved in the reaction.

D) The total number of atoms does not change, so mass is conserved in the reaction.

3.
Use the equation and the table to answer the question.

FeCl3 + 3H2O → Fe(OH)3 + 3HCl

Element Mass of an Atom (amu)
Fe 56
Cl 35
H 1
O 16
Iron chloride and water react according to the equation shown. The table shows the atomic masses of the elements involved in the reaction. What is the total mass of the reactants?

(1 point)

A) 215 amu

B) 179 amu

C) 161 amu

D) 108 amu

4. In a chemical reaction, two molecules with a total mass of 76 amu react to form a single molecule. What is the mass of the molecule that is formed?(1 point)

A) 228 amu

B) 38 amu

C) 76 amu

D) 152 amu

Answer:

There are many types of chemical reactions. In this chapter we will begin with combustion

reactions and end with oxidation/reduction reactions. Along the way we examine various aspects

of reactions.

Homework from the book:

Exercises: 1, 4, 6, 8, 9, 11,12, 14-19, 23, 25, 26, 29

Questions: none

Problems: none

In the study guide: Multiple 4, 5, 6, 12-18.

There are many types of chemical reactions. In this chapter we will begin with combustion

reactions and end with oxidation/reduction reactions. Along the way we examine various aspects

of reactions.

Combustion reactions:

All combustion reactions fall into the pattern:

fuel + O2 → CO2 + H2O

The coefficients of the balanced equation will change depending on the fuel. The fuel can be

almost anything including methane (CH4), propane (C3H8), butane (C4H10), octane (C8H18) or

sugar (C6H12O6).

The balanced equation for methane is CH4 + 2 O2 → CO2 + 2 H2O

The balanced equation for octane is

2 C8H18 + 25 O2 → 16 CO2 + 18 H2O

The combustion of methane or octane is exothermic; it releases energy.

CH4 + 2 O2 → CO2 + 2 H2O + energy

The energies of the products are lower than the energiies of the reactants. The excess energy is

released as heat and light.

Matter tends to move to lower energy states. A good analogy for a reaction is a ball falling down

a hill. Exothermic reactions are more likely to occur. Endothermic reactions absorb energy. In

these reactions the products are higher in energy than the reactants. Endothermic reactions are

less likely to occur. You seldom see a ball spontaneously going uphill. Endothermic reactions

can occur when entropy drives the reaction (pushes the ball up the hill). These reactions are far

less common. An exothermic reaction occurs in a chemical hot pack. (Skiers know about hand

and foot warmers.) An endothermic reaction occurs in a chemical cold pack.

The reaction in which the number of atoms are equal in both side is option A. The true statement regarding a chemical reaction is option D mass is conserved.

The total mass of reactants for the given reaction  is  179 g. The mass of the molecule formed will be 76 amu.

According to law of conservation of mass the total mass of the reactants is equal to the total mass of products in a reaction. No atoms are created or destroyed in a reaction.

1. The reaction in which the number of atoms are same on both side is option A, where both part contains 5 atoms.

2. According to mass conservation law, total number of atoms does not change, thus mass is conserved and option D is correct.

3. The atomic mass of Fe = 56 amu and the atomic mass of Cl = 35 amu. Mass of 3 Cl = 3×35 = 105 g

Thus mass of FeCl3 = 105 + 56 = 161 amu.

Mass of H = 1 amu and mass of O = 16 amu. Thus mass of 3 H2O = (3×(16+2)) =54 amu

Thus total mass = 54 + 161 = 215 amu

Thus, option A is correct.

4. According law of conservation of mass the total mass of reactant is equal to the total mass of products. Thus reactants of total mass 76 amu produce product of mass 76 amu. Thus option C is correct.

To learn more about mass conservation, refer the link below:

https://brainly.com/question/13702487

#SPJ2

What has to happen for these atoms/molecules to change from one state of matter to another? *view attachment*m

Which subatomic particles change the mass number? (select all that apply) Protons Neutrons Electrons

What is the relationship between Potential energy and Kinetic energy in a system?
its not chemistry ik
i will mark

as u move down the levels of classification the number of classification the number of organisms in the level decrease or increase?

Which equation using element symbols correctly describes the reaction: "One molecule of methane plus two molecules of diatomic oxygen react to form two molecules of water and one molecule of carbon dioxide?"

I need help ASAP! 10 points!

WILL GIVE BRAINLIEST
List three examples of where potential energy is transformed to kinetic energy in the Rube Goldberg Machine simulation. Fully explain the energy transformations using complete sentences. (Example: The ball has potential energy when it sits on the shelf that transforms to kinetic energy when it falls to the ground.)

DO NOT COPY AND PAST THE ANSWER FROM 2018 AND IF YOU HAVE A QUSTOIN ABOUT IT ASK UNDER THE QUSTION DO NOT ANSWER IT TO ASK A QUSTION

Which statement best describes properties of elements? A) All elements have a similar structure and hardness. B) All elements are either metals or gases. C) All elements are solid and magnetic. D) All elements have mass and occupy space

Match the atomic particles with their characteristics.

1. made of two protons and two neutrons
2. similar to an electron; positive charge
3. orbits nucleus; negative charge
4. bundle of energy; zero charge
5. found in nucleus; positive charge
6. very unstable; +, -, or zero charge
7. found in nucleus; zero charge
8. negative particle; negative charge
9. atomic energy converted to mass

Words to match to:
alpha
electron
positron
neutrino
proton
beta
gamma
neutron
meson

Which statement best describes what a circle graph shows?
A. A frequency distribution
B. Data as proportions of a whole
C. The average of a data set
D. The relationship between two variables

What causes objects to move or stay still?
Claim

Reasoning:

Evidence:

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I will give brainliest !!…

A student combined equal amounts of two solutions. One solution had a pH of 2 and the other had a pH of 12. Which would most likely be the resulting pH? 1 3 6 11

Obi is trying to determine if a powdery, solid substance is an element or a compound. After recording some observations, he strongly heats a sample of the solid over a burner flame. After fifteen minutes, he turns off the flame and allows the sample to cool. He records his final observations in the data table.

A 3-column table with 3 rows. The first column labeled observation has entries appearance, mass (g), chemical reaction with weak acid. The second column labeled original sample has entries white solid, 100.0, bubbles. The third column labeled sample after heating has entries white solid, 56.0, no bubbles.
Which is the best explanation of his results?

A. The heating changed some of the sample to gas, causing the mass to decrease without breaking down the sample. Therefore, the original sample is a compound.

B. The appearance stayed the same, showing that the sample was not broken down by heating. Therefore, the original substance is an element.

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In the early 1900s many scientists thought that an atom consisted of a positive substance with negative charges scattered throughout the substance. Then Ernest Rutherford made a discovery that led to the understanding that an atom consists mostly of empty space with- * 20 points A. protons orbiting a dense nucleus made of electrons and neutrons B. Neutrons and protons orbiting a cloud of electrons C. Electrons and protons orbiting a cloud of neutrons D. Electrons orbiting a dense nucleus made of protons and neutrons

235
92
U +
1
0
n →
90
36
Kr +
A
56
Ba + 3
1
0
n

Which of the following determines if a substance is pure or a mixture? Select all that apply. a . Whether the mixture changes color when you apply a flame. b. Whether the matter is in a solid, liquid, or gas state. c. Whether the parts can be separated by physical or chemical methods. d. Whether you can see the parts without a magnifying device.

Which property describes a mixture? It cannot be separated by physical methods. It has a single chemical composition. It cannot have more than one state of matter. It cannot be described by a chemical symbol or formula.

SCIENCE!! i need help on the question in the middle please!!!

Please match the example with the classification of matter in which it belongs. Column A 1. soil: soil 2. chocolate milk: chocolate milk 3. neon: neon 4. water: water Column B a.element b.homogeneous c.compound d.heterogeneous mixture

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Which statement correctly describes the location and charge of a proton in an atom? A. The protons are inside the nucleus with a negative charge. B. The protons are inside the nucleus with a positive charge C. The protons are outside the nucleus with a negative charge. D. The protons are outside the nucleus with a positive charge.

A group of people take a diet pill. After 3 months, they measure the amount of weight they lost.
A :Independent Variable:
B: Dependent Variable:

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A. 64
B. 65.5
C. 65
D. 66

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