In chemistry class, Allen determined the effectiveness of various metals in releasing hydrogen gas from hydrochloric acid. Several weeks later, Allen read that a utilities company was burying lead next to iron pipes to prevent rusting. Allen hypothesized that less rusting would occur with the more active metals. He placed the following into 4 separate beakers of water: (a) 1 iron nail, (b) 1 iron nail wrapped with an aluminum strip, (c) 1 iron nail wrapped with a magnesium strip, and (d) 1 iron nail wrapped with a lead strip. He used the same amount of water, equal amounts (mass) of the metals, and the same type of iron nails. At the end of 5 days, he rated the amount of rusting as small, moderate, or large. He also recorded the color of the water. What is the independent variable?
a) the amount of water
b) the metals strips
c) amount of rust
d) hydrochloric acid

Answers

Answer 1

Answer:

b) the metals strips

Explanation:

In an experimental design, an independent variable is a variable that is changed or manipulated in a series of experiments. An independent variable is not dependent on any other variable in the experiment. The hypothesis for this experiment is stated to be: "If the chemical activity of the metallic wrapper is increased, then less rusting of iron will occur. The independent variable relates to the type of metal wrapping strip, and the dependent variables are the amount of rusting and color of the water.


Related Questions

If the atomic number increases then the atomic radius should decrease right? So what’s wrong with my data

Answers

Answer:

Atomic radius increases by increasing the atomic number.

Explanation:

Atomic radius :

Atomic radius is the distance between nucleus of an atom to its outer most electronic shell.

Trend along group:

As we move down the group atomic radii increased with increase of atomic number. The addition of electron in next level cause the atomic radii to increased. The hold of nucleus on valance shell become weaker because of shielding of electrons thus size of atom increased.

As the size of atom increases the ionization energy from top to bottom also  decreases because it becomes easier to remove the electron because of less nuclear attraction and as more electrons are added the outer electrons becomes more shielded and away from nucleus.

The given data show that the atomic number in increased from 4 to 88 it means atomic radius also increased from 1.53Å to 2.83Å. It means the given data is the elements of periodic table present in group. It is the data of 2nd group of periodic table.

What is the difference between carbon-12, carbon-13, and carbon-14?

Answers

Answer:

Number of neutrons in the nucleus.

Explanation:

Mass number is protons plus neutrons. Protons do not change from isotope to isotope

increased amounta of carbon dioxide in Earth's atmosphere may lead to global warming. what might global warming then lead to ​

Answers

air temperatures increasing.

what is the needed electrons for CLO3-​

Answers

Each oxygen atom in the ClO3- ion already has two electrons the electrons in the Cl-O covalent bond. Because each oxygen atom needs six nonbonding electrons to satisfy its octet, it takes 18 nonbonding electrons to satisfy the three oxygen atoms.

A balloon filled with helium occupies 21.0ft³ at 55.0°F. Find the temperature of the helium if the volume of the balloon decreases to 11.0ft³. (Assume that the pressure is held constant.)​

Answers

Answer:

Assuming pressure is held constant,the question reduces to a ratio and proportion type of question where;

At constant pressure,

21.0ft³-55.0°F

11.0fy³=11.0ft³/21.0ft³×55°F

The temperature is 28.809°F≈29°F

29°F is the temperature of the helium if the volume of the balloon decreases to 11.0ft³.

What is temperature?

Temperature expresses hotness and coldness or a measure of the average kinetic energy of the atoms or molecules in the system.

Assuming pressure is held constant, the question reduces to a ratio and proportion type of question where;

At constant pressure,

21.0ft³- 55.0°F

11.0fy³ = 11.0ft³ ÷ 21.0ft³ × 55°F

The temperature is 28.809°F ≈ 29°F

Hence, 29°F is the temperature of the helium if the volume of the balloon decreases to 11.0ft³.

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C - chemical change
P- physical change

(Pls help me)

Answers

Answer:

Burning wood is a chemical change.  Burning wood is an example of a chemical reaction in which wood in the presence of heat and oxygen is transformed into carbon dioxide, water vapour, and ash.

Baking an apple pie is a physical change because the apples in the pie start changing physically and the pie crust starts hardening and rising up.

Explanation:

tell me about yourself

Answers

i play basketball and run cross country

Answer:

Tell picture above is a sample of tell me about yourself

Which is most likely the result of millions of metal atoms crowding together so that molecular orbitals become combined?

Answers

Answer:

(The Formation Of Bands In A Crystal)

The formation of bands in a crystal !! NdsmksjswGood luck on your assignment snsmskskmsjssiwndnsmsmsjwjw

The production of 2-methyl-2-phenyl propane. This would be a two-step synthesis.
Can someone explain what is this reaction ?

Answers

Sorry man, this isn’t really my cup of tea

Arrange the following in order of increasing atomic radius: Mg, Na, P, Si, and Ar.

Answers

Answer:

Ar, P, Si, Mg, Na

Explanation:

Ar=106pm

P=107pm

Si=111pm

Mg=141pm

Na=166pm

Na>Mg>Si>P>Ar is the order of increasing atomic radius.

What are elements?

Elements are the simplest substances which cannot be broken down using chemical methods.

Atomic radii vary in a predictable way along or across the periodic table. The atomic radius increases from top to bottom in a group, and decreases from left to right across a period. Thus we can say that helium is the smallest element, and francium is the largest.

Ar=106pm

P=107pm

Si=111pm

Mg=141pm

Na=166pm

Hence, Na>Mg>Si>P>Ar is the order of increasing atomic radius.

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10 divided by 2 im confused

Answers

if your serious about this question then it is 5

The awncer is 5!! Just use a Calculator and you would’ve gotten 5!!

Which describes a covalent bond?
a. Formed by the sharing of electrons between atoms

b. Formed by the giving and taking of electrons between atoms.

c. Formed by the forces of gravity between atoms.

d. Formed by sharing protons and neutrons between atoms

Answers

Answer:

a

Explanation:

covalent bonds are bonds between two nonmetals where they share an electron :)

Which of the following is a CHEMICAL CHANGE?
A- Buttering Toast
B- Melting ice Cream
C-An egg gives off a rotten smell
D-sugar is dissolved into water
E- baking soda mixed with vinegar forms bubbles
F- boiling water forms bubbles
G-Iron turns red as it rusts
H-Iron turns red as it is heated​

Answers

Answer:

G, but I think that theres more than one answer

What Happens When extra Solute is added to unsaturated ,saturated and supersaturated solution​

Answers

of water is 36.0 g. If any more NaCl is added past that point, it will not dissolve because the solution is saturated. If more solute is added and it does not dissolve, then the original solution was saturated. If the added solute dissolves, then the original solution was unsaturated.

What separation method collects vapor

Answers

Answer:

evaporation and distilation

Explanation:

Distillation. In distillation, components of a liquid mixture are separated on the basis of the differences in their boiling temperatures. In its simplest form, distillation involves boiling the mixture and collecting the vapor in a condensation vessel, where it turns back into a liquid.

A 200.0-mL sample of helium gas is in a cylinder with a movable piston at 110 kPa and 275 K. The piston is pushed in until the sample has a volume of 95.0 mL. The new temperature of the gas is 310. K. What is the new pressure of the sample?

51.1 kPa
261 kPa
249 kPa
274 kPa

Answers

Answer:

P₂ = 261 KPa

Explanation:

Given data:

Volume of sample = 200 mL

Initial pressure = 110 KPa

Initial temperature = 275 K

Final volume = 95 mL

Final temperature = 310 K

Final pressure = ?

Solution:

Formula:

P₁V₁/T₁ = P₂V₂/T₂

P₂ = P₁V₁T₂ /T₁ V₂

P₂ = 110 KPa× 200 mL× 310 K /275 K  × 95 mL

P₂ = 6820000 KPa / 26125

P₂ = 261 KPa

What data do scientists use to determine when a volcano might erupt?

Whoever gives me the right answer will get brainliest.

Answers

Answer:

seismographs

Explanation:

Scientists use seismographs that record the length and strength of each earthquake to try to determine if an eruption is imminent. Magma and gas can push the volcano's slope upward.

Select the conditions that are required for the formation of hurricanes. (Choose 3)
A: cold,cyclonic wind
B: deep ocean water
C: cold ocean water
D: warm,humid wind
E: warm ocean water
F: a strong cold front​

Answers

Answer:  

A: cold, cyclonic wind

B: deep ocean water

C: cold ocean water

E: warm ocean water

F: a strong cold front​

You only need A, B, C, E, F not D because that for tornadoes buddy.

What determines whether something is a solid, a liquid or a gas?

Answers

Also, how fast the molecules are moving within the state of matter and how spread out they are.

Fe (s) + Pb(NO3), (aq) —> ___

Type of reaction: _____

Answers

Answer:

lead , chemical

Explanation:

chemical ..........
..........

Which of the following is a true difference between protons and neutrons?

a
the have different masses
b
they are in different locations in the atom
c
the proton identifies the atom and the neutrons does not
d
all of the choices are true

Answers

Answer:

D

Explanation:

A control is....
A: What we measure
B: What we change
C: What we measure that does not have the variable we are testing.
D: What we conclude

Answers

C. You use the control to compare results

Can someone help me click the picture

Answers

Answer:

A product

B coefficient

C script

D rectant

write the correct representation of an element x which contains 12 electrons and 16 neutrons

Answers

Answer:

²⁸Mg

Explanation:

12 electrons means it is a Mg;

A typical Mg has 12 neutrons, but this has 16 hence it must be an isotope with 4 extra neutrons.

Which type of bond will chromium atoms likely to form with other chromium atoms
A:ionic
B:covalent
C:metallic

Answers

Answer: B

Explanation: Covalent bonds where electrons are not shared equally between two atoms are called polar covalent bond. As shown above, the electrons in a covalent bond between two different atoms (H and Cl in this case) are not equally shared by the atoms. This is due to the electronegativity difference between the two atoms.

There are two types of chemical compound one is covalent compound and other is ionic compound in chemistry. The covalent bond will be formed between two chromium atoms. the correct option is option B.

What is chemical Compound?

Chemical Compound is a combination of molecule, Molecule forms by combination of element and element forms by combination of atoms in fixed proportion.

Covalent bond formed by sharing of electron and ionic bond formed by complete transfer of electron.

Element with same electronegativity difference combine together by covalent bond whereas ionic bond is formed by elements whose electronegativity difference is high.

As two chromium is combining that is two two element with same electronegativity is combining therefore, formation of covalent bond is the only possibility.

Therefore covalent bond will be formed between two chromium atoms. the correct option is option B.

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How would an invasive species affect an ecosystem?
Group of answer choices

The invasive species would integrate easily into the ecosystem.

The invasive species would take over in the area and throw off the balance of the ecosystem.

The invasive species would balance the ecosystem.

The invasive species would change the abiotic factors in the area.

Answers

Answer:

The invasive species would take over in the area and throw off the balance of the ecosystem.

Explanation:

Invasive species can harm both the natural resources in an ecosystem as well as threaten human use of these resources. An invasive species can be introduced to a new area via the ballast water of oceangoing ships, intentional and accidental releases of aquaculture species, aquarium specimens or bait, and other means.

Invasive species are capable of causing extinctions of native plants and animals, reducing biodiversity, competing with native organisms for limited resources, and altering habitats. This can result in huge economic impacts and fundamental disruptions of coastal and Great Lakes ecosystems.

Hope this helped!

Sodium will do an ionic bond with

Answers

Answer:

Chorine

Explanation:

It's a classic, sodium chloride, table salt, which is an ionic bond.

PLS GIVE BRAINLIEST

Which of these properties can be used to separate mixtures? - characteristic properties *
1. state of matter
2. mass
3. volume
4. boiling/melting point
5. density
6. conductivity
7. solubility

Answers

Answer:

Boiling/melting point

Explanation:

Some elements can’t handle the heat nor the cold, so they separate like oil & water.

The answer is boiling/melting point

Describe the two types of mechanical energy

Answers

Answer:

Kinetic energy and potential energy

Explanation:

kinetic energy is when the energy is active and potential energy is when it is about to be active

Bobbye wants to know how his speed affect the amount of time it takes to stop at a stop sign. Each time he performs a trial, he will change the speed that he is driving to see how it affects the amount of time it takes to stop. ​ Independent Variable:​ ​ ​ Dependent Variable:​ ​ ​ Controlled Variables:​

Answers

Answer:

The correct answer is -

Independent Variable:​ change of speed​ ​

Dependent Variable:​ time takes to stop​ ​

Controlled Variables:​ stop at a stop sign

Explanation:

To know the effect of the speed to take the time to stop at a stop sign Bobbye perform this exercise where he changes the speed at each time that he is driving to know the time it takes to stop at a stop sign. There is a change that takes place purposely is in the speed of driving so it is an independent variable as the independent variable is a variable that is manipulated in an experiment or investigation.

The time it takes to stop is the factor that depends on the speed so it is the dependent variable as the dependent variable is the variable that depends on the independent variable.

The control variable remains the same or constant in an investigation which is stoping at a stop time irrespective of speed.  

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