PLEASE HURRY IM TIMED Which of the following are examples of physical changes? (Select all that apply.)
tearing a piece of paper
a nail rusting
crushing a soda can

Answers

Answer 1

Answer:

Explanation:

tearing a piece of paper

crushing a soda can


Related Questions

How many particles are in 4g of NaCl? (1mol of NaCl = 58g) – 2 step conversion

Answers

Answer:

4.16 * 10²⁴ particles

Explanation:

1. We convert from grams to moles

4 g NaCl / 58 g of NaCl = 0.0689655172 moles

-> 0.0690 moles

2. Now we will convert from moles to particles by multiplying by avogadro's number..

0.0690 * 6.022 *10²³ = 4.15518 * 10²⁴ particles or 4.16 * 10²⁴ particles

What is an electrolytic cell?

Answers

Answer:

An electrolytic cell is a cell that converts electrical energy into chemical energy.

Any device in which electrical energy is converted to chemical energy or vice versa is referred to as an electrolytic cell. A typical cell consists of two metallic or electronic conductors held apart and in contact with an electrolyte, which is usually a dissolved or fused ionic compound.

What is an electrolytic cell ?

An electrolytic cell is a type of electrochemical cell that uses an external source of electrical energy to force a chemical reaction that would not occur otherwise. A voltage applied between the cell's two electrodes, an anode and a cathode immersed in an electrolyte solution, serves as the external energy source.

Electrons in the form of an electric current are deliberately pumped through the chemicals in the section to induce an oxidation-reduction reaction. An electrolytic cell is a setup used to electrolytically decompose water into hydrogen and oxygen.

Electrochemical cells that generate an electric current are known as voltaic or galvanic cells, whereas those that generate chemical reactions, such as electrolysis, are known as electrolytic cells.

Thus, Any device in which electrical energy is converted to chemical energy or vice versa is referred to as an electrolytic cell.

To learn more about electrolytic cell, follow the link;

https://brainly.com/question/4030224

#SPJ5

Is water made of plant cells or animal cells
•plant
•animals
•niether

Answers

Answer:

i think niether

Explanation:

Which represents the overall (net) reaction of this mechanism: step 1: H2O2 + I- → H2O + OI- step 2: H2O2 + OI- → H2O + O2 + I- Note that I- acts as a catalyst in this reaction.


A. 2H2O2 → 2H2O + O2

B. H2O2 → H2 + O2

C. H2O2 + I- → OI- + H2O

D. H2O2 + OI- → H2O + O2 + I-

Answers

Answer:

A. 2H₂O₂  → 2H₂O + O₂

Explanation:

1. H₂O₂ + I⁻ → H₂O + OI⁻2. H₂O₂ + OI⁻ → H₂O + O₂ + I⁻

If we make a net sum of both reactions, we're left with:

H₂O₂ + I⁻ + H₂O₂ + OI⁻ → H₂O + OI⁻ + H₂O + O₂ + I⁻

Grouping species:

2H₂O₂ + OI⁻ + I⁻ → 2H₂O + OI⁻ + O₂ + I⁻

There is OI⁻ at both sides, so it is eliminated -same goes for the catalyst, I⁻-.

2H₂O₂  → 2H₂O + O₂

Thus the answer is option A.

(b) Why must acidic gases be treated before they are released into the atmosphere?

Answers

Answer:

because they react with other gases of atmosphere and pollute the environment

Determine the molecular formula for a compound that has a molecular mass of 52.0 g/mole
and and is composed of 92.31% carbon and 7.69% hydrogen.

Answers

Answer:

C4H4

Explanation:

92.31% of 52.0 g/mol is 48.0012 g/mol

7.69% of 52.0 g/mol is is 3.9988 g/mol

Carbon has a gram-formula mass of about 12, which goes into 48.0012 about 4 times, so there should be 4 atoms of Carbon

Hydrogen has a gram-formula mass of about 1, which goes into 3.9988 about 4 times, so there should also be 4 atoms of hydrogen

For the balanced equation shown below, what would be the limiting reagent if 42.3 grams
of N2O5 were reacted with 9.18 grams of H2O?
N2O5+H2O---> 2HNO3

A. HNO3
B. H20
C. N205

Answers

Answer: A. HNO3

Explanation:

what is the chemical equation for methamphetamine ​

Answers

Answer:

C10H15N is the chemical equation for methamphetamine

The chemical formula for methamphetamine or meth is C10H15N

The compound cobalt (II) sulfate forms a hydrate with seven water molecules per formula unit. What are the name and formula of the hydrate

Answers

Answer: The formula of the hydrate will be [tex]CuSO_4.7H_2O[/tex] and the name of the compound is copper sulphate heptahydrate.

Explanation:

Water of crystallisation is the number of water molecules that combine chemically in definite molecular proportion with the concerned salt in the crystalline state.

The formula of the hydrate will be [tex]CuSO_4.7H_2O[/tex] and the name of the compound is copper (II) sulphate heptahydrate as there are 7 molecules of water.

K2HPO4 is a highly water-soluble salt. It can be used as a buffering agent, food additive, or
fertilizer. The neutralization of phosphoric acid with potassium hydroxide can be used to form
potassium hydrogen phosphate.
H3PO4 + 2KOH K2HPO4 + 2H2O
100 g of phosphoric acid (H3PO4) is reacted with excess potassium hydroxide. The final mass
of K2HPO4 produced is found to be 163 g.
What is the percent yield?

Answers

Answer:

91.7%

Explanation:

The percent yield when it could be used as a buffering agent should be considered as the 91.74%.

Calculation of the percent yield:

Since we know that

Number of moles = Mass in gram / Molar mass

And,

Molar mass of H3PO4 = 97.994 g/mol

So,

Number of moles of H3PO4

= 100 g / 97.994 g/mol

= 1.02 mol

Now

Molar mass of K2HPO4 = 174.2 g/mol

So,

Theoretical yield of K2HPO4 = 174.2 g/mol * 1.02 mol

= 177.684 g

So finally

Percent yield = Actual yield * 100 / Theoretical yield

= 163 g * 100 / 177.684 g

= 91.74%

hence, The percent yield when it could be used as a buffering agent should be considered as the 91.74%.

learn more about percentage here: https://brainly.com/question/14849541

Which of the following sources could not be used to obtain the DNA of a person lost in a mass disaster? used and unwashed clothing or bed sheets food found in the victim's refrigerator sunglasses regularly used by the person a toothbrush used by the person

Answers

Question :

Which of the following sources could not be used to obtain the DNA of a person lost in a mass disaster?

used and unwashed clothing or bed sheetsfood found in the victim's refrigeratorsunglasses regularly used by the persona toothbrush used by the person

Answer :

food found in the victim's refrigerator could not be used to obtain the DNA of a person lost in a mass disaster.

So, correct answer is 2nd one.


help asap pls,
find the percent composition

Answers

Explanation:

1. Pb(CO3)2

Element Number Mass Percet Composition

Oxygen 6 16.00 29.34%

Carbon 2 12.01 7.34%

Lead 1 207.21 63.32%

2. Ga(OH)3

Element Number Mass Percet Composition

Hydrogen 3 1.0079 2.50%

Oxygen. 3 16.00 39.75%

Gallium 1 69.72 57.74%

3. P4O10

Element Number Mass Percet Composition

Oxygen. 10 16.00. 56.36%

Phosphorus. 4 30.97 43.64%

4. Ca3P2

Element Number Mass Percet Composition

Phosphorus 2 30.97 34.00%

Calcium. 3 40.08 66.00%

5. Ti(NO3)3

Element Number Mass Percet Composition

Oxygen. 9 16.00 61.56%

Titanium. 1 47.87 20.47%

Nitrogen. 3 14.01 17.97%

Choose the combination of factors that creates fog. Record the description of the factors in the Student Guide,

Relative Humidity


Air Temperature


Air Pressure


Check

Pause

Answers

Answer:

Relative Humidity

Air Temperature

Explanation:

Relative humidity  and air temperature are the factors that creates fog. When the moist and warm air makes contact with the cooler air, water vapor condenses due to low temperature of that region that causes for the formation of fog. So we can say that relative humidity  and air temperature are the main factors for the formation of fog in that region.

Answer:

High Cold High

Explanation:

pls help me on this it's about acceleration​

Answers

Answer:

1: A b/c the table is showing that each different surface resulted in different time for acceleration.

2: D b/c the if the same force is applied to two different masses, the smaller masses would be impacted more and move faster. The larger an object is, then the greater the force you will need for it to move the same distance as the smaller masses.

Which of these statements is false?
A. All matter is made up of atoms.
B. Atoms are made up of protons,
neutrons, and electrons.
C. Atoms contain chemical bonds.
D. Atoms are the smallest particles of
elements.

Answers

Answer:

C is the false one atoms contain chemical bonds

Answer:

C. Atoms contain chemical bonds.

Reason:

Atoms don't have any chemical bonds. Molecules are the particles have chemical bonds.

b. If you have 50 grams of Molybdenum-99, how many grams will remain
after 11 days?

Answers

Answer:

6.25gm

half life is 66hrs 11 days is 24*11 then take that and divide by 66 to find out how many time it will have halved and half 50 by that many times

Explanation:

If you have 50 grams of Molybdenum-99, after 11 days, 2.7 g will remain.

Molybdenum-99 follows first-order decay.

What is first-order decay?

First-order decay means that for a population of atoms (e.g. radioactive), molecules, or anything else, a constant fraction/unit time is converted to something else.

The half-life (th) of Mo-99 is 66 h.

We will find its rate constant (k) using the following expression.

k = ln2 / th = ln2 / 66 h = 0.011 h⁻¹

Next, we will convert 11 days to hours, knowing that 1 day = 24 h.

11 d × 24 h/1 d = 264 h

If we start with 50 g of Mo-99, we can calculate the remaining mass after 264 h using the following expression.

[tex][Mo] = [Mo]_0 \times e ^{-k \times t} }\\\\[Mo] = 50g \times e ^{-0.011 h^{-1} \times 264 h} } = 2.7 g[/tex]

where,

[Mo] is the final amount of Mo-99.[Mo]₀ is the initial amount of Mo-99.t is the elapsed time.

If you have 50 grams of Molybdenum-99, after 11 days, 2.7 g will remain.

Learn more about first-order decay here: https://brainly.com/question/14478152

Given the atomic mass of select elements, calculate the molar mass of each salt.

Element Molar mass
(g/mol)
Beryllium (Be) 9.012
Magnesium (Mg) 24.31
Cobalt (Co) 58.93
Cadmium (Cd) 112.41
Bromine (Br) 79.90
Match the numbers to the appropriate blanks in the sentences below. Make certain each sentence is complete before submitting your answer.
View Available Hint(s)
ResetHelp
1. The molar mass of MgBr2 is The molar mass of M g B r 2 is blank..
2. The molar mass of BeBr2 is The molar mass of B e B r 2 is blank..
3. The molar mass of CoBr2 is The molar mass of C o B r 2 is blank..
4. The molar mass of CdBr2 is The molar mass of C d B r 2 is blank..

Answers

1. 184.11
2. 168.812
3. 218.13
4. 272.21

Zn(s) + 2 HCl(aq) —> ZnCl2(aq)
+ H2(g)
If a scientist wanted to create 10L of hydrogen gas at RTP, what mass of HCl would they need to start with?

Answers

Answer:

First write the balanced equation for the reaction of HCl with Zn (NOTE: the previous answer did NOT do this and thus obtained an incorrect answer)

Zn + 2HCl ==> ZnCl2 + H2(g)

moles of H2 desired:  PV = nRT

n = PV/RT = (1 atm)(10L)/(0.0821 Latm/Kmol)(298K)

n = 0.409 mole H2 desired

moles Zn needed:

0.409 moles H2 x 1 mole Zn/2 moles HCl = 0.204 moles Zn needed

mass Zn needed = 0.204 moles Zn x 65.4 g/mol = 13.4 g Zn needed (to 3 sig. figs.)

Explanation:people always get this wrong but i got you

Which of the following is an ether?
A)
B)
C)
D)

Answers

B because it shows the COOCH

Please help :) hope you have a good day

Answers

Have a wonderful day :) thanks for the points

1. Mixing Water at Two Temperatures
a. One flask contains 150.0 g water at 20.0 °C. A second flask contains 350.0 g water at 95.0 °C. If the two water samples are mixed, what will the final temperature of the water be?
-Assume that the density of water it 1.000 g/cm^3
-The specific heat capacity for water is 4.184 J/g °C​

Answers

Answer:

[tex]T_f=72.5\°C[/tex]

Explanation:

Hello!

In this case, since this a problem in which the cold water is heated by the hot water, we can write:

[tex]Q_{hot}+Q_{cold}=0[/tex]

Thus, by plugging in the mass, specific heat and temperatures, we obtain:

[tex]m_{hot}C_{hot}(T_f-T_{hot})+m_{cold}C_{cold}(T_f-T_{cold})=0[/tex]

Now, we can also write:

[tex]m_{hot}(T_f-T_{hot})+m_{cold}(T_f-T_{cold})=0[/tex]

Then, after applying some algebra, it is possible to obtain:

[tex]T_f=\frac{m_{hot}T_{hot}+m_{cold}T_{cold}}{m_{hot}+m_{cold}}[/tex]

If we plug in, we obtain:

[tex]T_f=\frac{350.0g*95.0\°C+150.0g*20.0\°C}{350.0g+150.0g}[/tex]

[tex]T_f=72.5\°C[/tex]

Best regards!

neptune has an average distance to the sun of 30.06 au in two or more complete sentences explain how to calculate the orbital period of neptune ​

Answers

Answer:

As per Kepler's law we know that

\frac{T_1^2}{T_2^2} = \frac{R_1^3}{R_2^3}T22T12=R23R13

as we know that for earth the time period is 1 year and its distance is 1 AUnow from above formula we can saylet the time period of Neptune is T and its distance is given as R = 30.06 AUnow we will have\frac{1^2}{T^2} = \frac{1^3}{30.06^3}T212=30.06313by rearranging the above equation we haveT^2 = (30.06)^3T2=(30.06)3T = 164.8 yearsT=164.8years

so it will have time period of 164.8 years

Hello, this is a science task and it is due today I would really appreciate it if you guys can help me answer and explain what is the difference between expansion and contraction:) I will mark brainliest!

Answers

Answer:

Expansion: increase in size Contraction: decrease in size

Explanation:

The increase in size of an object on heating is called expansion where as the decrease in size of an object on cooling is called contraction.

Which of the following particles has the smallest
mass?
A) electron
C) neutron
B) hydrogen atom
D) proton

Answers

Answer:

AN ELECTRON HAS THE SMALLEST MASS!

Answer:

A) electron

good luck, i hope this helps :)

3.Which of these is NOT part of the cell theory? * "

all living things are made of cells
Ocells come only from other cells
cells are the smallest living unit of an organism
O all living things have blood cells

Answers

Answer:

Cells are the smallest living unit of an organism

Answer:

all living things living things have blood cells

Explanation:

this is because robert hooke did not make this apart of the theory

name the two criteria that is used to determine if a substance is pure or not​

Answers

Answer:

Melting and Boiling Point Determination

The physical properties of a substance can be used to establish its purity. These properties include the melting point and boiling point. Different substances tend to have different melting and boiling points, and any pure substance will have a specific melting and boiling point.

Antonio and Addie want to know if perfume fumes affect plant height. They place five identical bean plants in five identical light boxes. In four of the boxes, they place 200 milliliters (mL) of perfume at different distances from the plants, and they make observations twice a week for one month. Which choice best identifies the observation data that should be included in their data table?

Answers

Answer:

I think its C I'm sorry if I'm wrong good luck guys!

Explanation:

Name this branched alkane shown in Figure 18-1.

Answers

Answer:

3–ethyl–2,2–dimethylhexane

Explanation:

To name the compound given in the question above, do the following:

1. Determine the parent name by determining the longest continuous carbon chain. In this case, the longest continuous carbon chain is 6. Hence, the parent name is Hexane.

2. Identify the substituent group attached to the compound. In this case, we have one ethly group (–CH₂CH₃) and two methyl groups (–CH₃)

3. Locate the position of the substituents by giving them the lowest possible count. In this case,

The two methyl groups (–CH₃) are located at carbon 2

The ethly group (–CH₂CH₃) is located at carbon 3.

4. Combine the above to obtain the name of the compound.

The name of the compound is:

3–ethyl–2,2–dimethylhexane

#3. How does a fever aid an immune response?

Answers

Answer:

it can tell and show what pathogen is in you as well what type and mutation so then your body can fight back and remember the genetic dna so then you will be immune in some way.

Explanation:

Question;

How does a fever aid an immune response?

Answer:

One type of immune cell jumps into the fray after body temperature rises, according to experiments in mice. A fever fights infection by helping immune cells to crawl along blood-vessel walls to attack invading microbes

Please help it really important, I will mark brainliest please

Answers

Answer:

S0rRy i d0nT kn0w fRenCh

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