A chemical reaction is shown.

SnO2 + H2 → Sn + H2O

What is true about this chemical reaction?

A.
It is balanced because the mass of the reactants (number of atoms) is equal to the mass of the products (number of atoms).

B.
It is unbalanced because the mass of the reactants (number of atoms) is greater than the mass of the products (number of atoms).

C.
It is unbalanced because the mass of the reactants (number of atoms) is less than the mass of the products (number of atoms).

D.
It is balanced because the number of reactants (number of atoms) is equal to the number of products (number of atoms).

Read the information about an experiment.


Jadon plans on carrying out an experiment involving the burning of steel wool to illustrate the conservation of mass. Steel wool is made of iron. When it is burned it combines with oxygen to form iron(III) oxide.

Which step in his experiment is the most important if he wants his experiment to correctly demonstrate the conservation of mass?

A.
The steel wool should be burned inside of a sealed jar or other closed system.

B.
The steel wool should be burned over a long period of time (at least two hours).

C.
The steel wool should be burned in a room that is at room temperature (20–25°C).

D.
The steel wool should be burned in its entirety sExpected Outcomes – Metals in Hydrochloric Acid

Metal Observations
Copper No reaction even when gently heated
Iron Little initial reaction.
More vigorous reaction when heated.
Positive test for hydrogen gas.
Solution turned from colorless to yellow.
Magnesium Vigorous initial reaction; rapid evolution of gas.
Positive test for hydrogen gas.
All of the magnesium seemed to disappear.
Solution remained colorless.
Zinc Initial reaction produced rapid evolution of gas; less vigorous than magnesium.
All of the zinc seemed to disappear.
Solution remained colorless.


Students in Ms. Brown's Science Lab demonstrated several chemical reactions, by placing the each above chemicals in HCl (hydrochloric acid). Unfortunately, the data did not appear to support the Law of Conservation of Matter in any of the experiments. The recorded Mass of the Reactants did not match the Mass of the Products. Based on the expected outcomes listed in the table above, what might be a reason that their demonstrations were not successful?
A.
They only used metals

B.
They perfomed the experiment in a closed system

C.
The experiment was not performed in a closed system

D.
They didn't use enough HCl that no iron is left in its original state.

Answer:

1) A chemical reaction is shown.

SnO2 + H2 → Sn + H2O

What is true about this chemical reaction?

B.

It is unbalanced because the mass of the reactants (number of atoms) is greater than the mass of the products (number of atoms).

2) Read the information about an experiment.  

Jadon plans on carrying out an experiment involving the burning of steel wool to illustrate the conservation of mass. Steel wool is made of iron. When it is burned it combines with oxygen to form iron(III) oxide.

Which step in his experiment is the most important if he wants his experiment to correctly demonstrate the conservation of mass?

A.

The steel wool should be burned inside of a sealed jar or other closed system.

Explanation:

The explanation to number 1 is that I selected it in my test and got it.

The explanation the number 2 is from the link below:

https://quizizz.com/admin/quiz/5dee60258f1145001bc02ed5/physical-science-2nd-9-weeks-practice-test-2020

The true statement about the given chemical reaction is-It is balanced because the mass of the reactants (number of atoms) is equal to the mass of the products (number of atoms). Therefore, the correct options for all the problems are 1-A, 2-A and 3-D.

A balanced equation refers to an equation where the number of atoms of each element is the same on both sides of the equation. The given equation is balanced because the number of Sn atoms and the number of H atoms on the reactant side are equal to the number of Sn atoms and the number of H atoms on the product side.

1. The steel wool should be burned inside a sealed jar or other closed system is the most important step if he wants his experiment to correctly demonstrate the conservation of mass.

2. They didn't use enough HCl that no iron is left in its original state might be a reason that their demonstrations were not successful.

Therefore, the correct options are 1-A, 2-A and 3-D.

Learn more about balanced equation, here:

https://brainly.com/question/29764227

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What factor causes global wind patterns

PLZ HELP ME ASAP


Read the article above and answer the following questions


1. The cardiovascular system includes:

A. the heart

B. blood

C. blood vessels

D. all of the above


2. Which of the following is NOT carried through the body by blood?

A. valves

B. carbon dioxide

C. nutrients

D. oxygen


3. Which of the following carries blood out of the heart?

A. arteries

B. veins

C. blood vessels

D. tubes


4. Which of the following is NOT a part of blood?

A. red blood cells

B. white blood cells

C. gorta

D. plasma


5. What is the heart largely composed of?

A. plasma

B. platelets

C. muscle

D. both B and C

Which RNA molecule is matched with its correct function?

What is a mold? in fossils​

Chromosomes are...

A.DNA material coiled up in a pile
B.DNA material in pairs
C. DNA material in single strands
D. DNA material outside of the nuclear membrane
WILL GIVE BRAINLIEST

A scientist found an igneous rock that contained pyroxene and plagioclase. What would best help the scientist to correctly classify the rock?

A. Identifying the rock as either intrusive or extrusive

B. Observing the color of the rock based on minerals

C. Knowing the additional minerals found in the rock

D. Determining the amount of pyroxene in the rock

1.) A person walks 12.5 km in 1.9 h. What is the person's
average velocity in km/h and m/s?

A cluster of cases of legionellosis have occurred in your neighborhood. People with the illness have cough, fever, shortness of breath, chest pain and sometimes diarrhea. The illness is caused by the bacterium Legionella pneumophila, a facultative intracellular parasite that survives in certain ameba. The organism has an absolute requirement for L-cysteine. Typically, the organism is grown on buffered charcoal yeast extract (BCYE) agar. In some labs, samples containing suspected L. pneumophila are cultured on traditional BCYE medium as well as BCYE medium lacking L-cysteine. How would L. pneumohila be identified in this situation

How is dopamine involved in drug addiction?


1) drugs change dopamine into another neurotransmitter.

2) drugs cause the reabsorption of dopamine.

3) drugs decrease dopamine levels in the brain.

4) drugs increase the level of dopamine in the brain









Answer and I will give you brainiliest
​

PLEASSEEE HELP ASAP THANKS ​

What structures have parasite worms lost? What structures/organs are expanded?

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Which animal will use a hollowed-out tree stump as a home?
O A) a beaver
OB) a bear
OC) an eagle
OD) a rabbit

What conclusion can you draw from the results shown?

A)The amount of the drug was decreased to achieve the same effect.

B) The mouse is in a state of tolerance.

C) The mouse is suffering from withdrawal symptoms.

D) The amount of drug injected was the same throughout the 7 weeks.

Answer and I will give you brainiliest
​

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WRONG ANSWERS ONLY!!! What is coastal runoff and what does it affect

Dave is perched on a tree branch. Which factor determines his potential energy?

(((25 POINTSS!!!! DUE SOON!! PLS HELP)))
The table below shows the number of rabbits living in an area of forest over 4 different generations. The table also breaks down their population size by fur color. Which statement below gives the best explanation of this data?

image link: https://imagebank.illuminateed.com/imagebank/1357110

After the pocket of magma slowly cools, what does the magma become?

A. Intrusive igneous rock

B. Extrusive igneous rock

C. Sedimentary rock

D. Metamorphic rock

competition a type symbiotic relationship is where

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Explain what causes a muscle to go into rigor mortis. Your answer should include the circumstances which cause it, as well as why those circumstances cause the effect (what is happening in the muscle at a molecular level which causes the stiffness). ​

Helppppppppppppppppppppppppp

If air pollution increases enough to begin reducing the amount of solar radiation to
reach the surface of the earth,
A. the ocean's thermocline would be directly affected
B. the salinity of the surface of the ocean would not be affected
C. the ocean would no longer be layered
D. more oxygen could be stored in the ocean

How do diet and weigh loss companies use bias to sell their products

Do natural hazards always become natural disasters? What are some things that people can do that might influence whether or not a natural hazard will become a natural disaster?

You have been studying two Hippogriff traits as a senior graduation project at Hogwarts (because you are magical), beak size (big beaks, B, are dominant to small beaks, b) and feather color (brown feathers, F, are dominant to white feathers, f). You mate two brown, big-beaked Hippogriffs and obtain the following results: 15 of the baby Griffs are brown and big-beaked; 4 of the baby Griffs are white are big-beaked; and 1 of the baby Griffs is white and small-beaked. What are the genotypes of the parent Hippogriffs

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In rabbits, black fur (B) is dominant to white fur (b) A purebred black furred male is bred with a female that had the recessive white fur

What percent of energy is transferred from the sun to the level indicated? (3 points)
50 percent
100 percent
90 percent
10 percent

pulled upwards in the trunk of a tall tree Ichestue
S. Give three reasons to explain why transpiration occurs mainly through leaves
6. Explain how sunken stomata lower the rate of transpiration
11
with
ftri​

In a separate study, 68 rock pocket mice were collected from four different, widely separated areas of dark lava rock. One collecting site was in Sonora, Mexico. The other three were in Chihuahua, Mexico. Dr. Nachman and colleagues observed no significant differences in the color of the rocks in the four locations sampled. However, the dark-colored mice from the three Chihuahua locations were slightly darker than the dark-colored mice from the Sonora population. The entire Mc1r gene was sequenced in all 68 of the mice collected. The mutations responsible for the dark fur color in the Sonora mice were absent from the three different populations of Chihuahua mice. No Mc1r mutations were associated with dark fur color in the Chihuahua populations. These findings suggest that adaptive dark coloration has occurred at least twice in the rock pocket mouse and that these similar phenotypic changes have different genetic bases.