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:
dependent variable I think
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.
C. The mass decreased during heating and some of the impurities escaped. Therefore, the original substance is an element.
D. The chemical reaction with acid changed, showing that the sample was broken down by heating. Therefore, the original substance is a compound.
An element consists of one type of atom and cannot be broken into simpler substances through simple chemical processes
The correct option is option D
D. The chemical reaction with acid changed, showing that the sample was broken down by heating. Therefore, the original substance is a compound
The reason why option D is correct is as follows:
The given table is presented as follows;
[tex]\begin{array}{|l|l|l|}\mathbf{Observation}&\mathbf{Original \ Sample}&\mathbf{Sample \ After \ Heating}\\Appearance&White \ solid&White \ solid\\Mass&100 \, g&56 \, g\\Chemical \ reaction \ with \ acid&Bubbles&No \ bubbles\end{array}\right][/tex]
Given that the changes after heating includes lack of visible reaction with the weak acid, and a significant change in mass, therefore;
The original substance was broken down by heat resulting in a new substance that has different chemical properties. An element cannot be broken down into simpler substances. Therefore, the substance is a compound
The correct option is option D
Learn more about elements and compounds here:
https://brainly.com/question/24701901
What element is this? Ignore my answer choice.
Answer:
Aluminum
Explanation:
It is your choice because only aluminum has 13 protons
Answer:
yea its aluminum the 13 element because of its 13 protons
Two students make a model of a tree house they want to build. The sale is 1:44. In the scale model, the tree house has 2 windows. How many windows should be the real tree house have?
A. 22
B. 88
C. 4
D. 2
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
Answer:
D(pretty sure)
Explanation:
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.
What mass conservation?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 causes objects to move or stay still?
Claim
Reasoning:
Evidence:
Answer:
For an object to move, there must be a force. A force is a push or pull that causes an object to move, change direction, change speed, or stop. Without a force, an object that is moving will continue to move and an object at rest will remain at rest.
Explanation:
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?"
Answer:
CH4+2O2→2H2O+CO2
You are looking at two samples of iron. One sample is very small and came from the red soil on the planet Mars. The other sample is very large and came from Earth's core. True or False, these two samples contain different atoms
What is the chemical symbol for table salt?
Answer: NaCI
Explanation:
Answer: NaCl
Sodium chloride , commonly known as salt (although sea salt also contains other chemical salts), is an ionic compound with the chemical formula NaCl, representing a 1:1 ratio of sodium and chloride ions.
Which subatomic particles change the mass number? (select all that apply) Protons Neutrons Electrons
Answer:
protons and neutrons pretty sure
Explanation:
The height of a coffee mug would be about:
a 500 mm
b 20 cm
c 1 km
d 8 cm
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
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.
Answer:
free trees
Explanation:
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
Answer:
D
Explanation:
That is the right answer
Please help me identify the element. The picture is blurry so..
Answer:
Explanation:
aluminium
The woman riding the bike applies a force by pedaling the bike. However, she moves at a constant velocity. So her force must be balanced by another force. What force acts to balance her forward force?
Frictional Force is the one and only.
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.
Answer:
it cannot be separated by physical methods
Explanation:
The mixture is not separated from the physical methods. Thus, option A is correct.
A mixture has been the combination of two or more substances. It has been described as a homogeneous solution.
The constituents in the mixture are indispensable. The mixture is generally homogeneous, however, heterogeneous mixtures have been possible with the substances being separated.
The mixtures have a different chemical composition and are not separated from the physical methods. Thus, option A is correct.
For more information about mixtures, refer to the link:
https://brainly.com/question/24898889
The data table shows the number of pumpkin seeds that germinate at different temperatures. What is the median number of seeds that germinate at 32ºC?
A. 64
B. 65.5
C. 65
D. 66
Answer: I agree with the other person it's B
What is the formula name!!
I will give brainliest !!…
Answer:
I think this is the formula CH₃COOH.
Explanation:
Where does the force come from when a bumper car changes speed?
Answer:
Newton's second law
Explanation:
The rate of change of momentum of an object is equal to the net force acting on it. When bumper cars collide they push on each other. These pushes cause the momentum of each car to change.
The engine............
235
92
U +
1
0
n →
90
36
Kr +
A
56
Ba + 3
1
0
n
Answer:
A= 143 B=146 C=56
Answer:
A: 143
B: 146
C: 56
Explanation:
2. When the child is pushed in the toy car, he increases speed. Does he accelerate as he is being pushed?
What has to happen for these atoms/molecules to change from one state of matter to another? *view attachment*m
Answer:thermal energy has to be added or transferred
Explanation:I’m not sure you might want to double check but the reason I chose thermal energy is because when thermal energy is added to liquid it may dissolve into gas
Write down Newton’s second law and its equation.
Answer: a = Fnet/m
Explanation:
The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object. This verbal statement can be expressed in equation form as follows: a = Fnet / m.
DO NOT ANSWER IF YOU DO NOT KNOW WHAT TO DO
Answer:
im gunna save my answer so no one can take it:)
Explanation:
I tried my best
Answer:
Wxvylaura
Explanation:
They are correct listen to them
As the toy car rolls away, it slows down. Why?
Answer:
Friction
Explanation:
Depending on the material the toy car rolls away on, the more friction is created, the more friction there is, the more on surface rubs against another, creating friction, slowing it down
hope this helps
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
Answer:
1. The ball will have potential energy at the top of the mountain, when the ball falls the ball will have kinetic energy .
2. The roller coaster has potential energy when stopped on the very top, therefore it releases kinetic energy when it falls down the rollercoaster.
3. The car on the hill had potential energy weather when it went down it had kinetic energy.
Explanation:
Sorry it took forever I had to think lol..
Answer:
ok lol
im bored
Explanation:
SCIENCE!! i need help on the question in the middle please!!!
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
Answer:
6
Explanation:
Answer:
6
Explanation: