which sample is a pure substance?
a. a test tube of zinc oxide
b. a container of zinc and oxygen
c. a flask of pond water
d. a jar of soil

Answers

Answer 1

Answer:

The answer is A. Test Tube of zinc oxide


Related Questions

A chemist must prepare of aqueous copper(II) sulfate working solution. He'll do this by pouring out some aqueous copper(II) sulfate stock solution into a graduated cylinder and diluting it with distilled water. Calculate the volume in of the copper(II) sulfate stock solution that the chemist should pour out. Be sure your answer has the correct number of significant digits.

Answers

Answer:

380 mL

Explanation:

A chemist must prepare 925 mL of 325 mM aqueous copper(II) sulfate working solution. He'll do this by pouring out some 0.792 M aqueous copper(II) sulfate stock solution into a graduated cylinder and diluting it with distilled water. Calculate the volume in mL of the copper(II) sulfate stock solution that the chemist should pour out. Be sure your answer has the correct number of significant digits.

Step 1: Given data

Initial concentration (C₁): 0.792 MInitial volume (V₁): ?Final concentration (C₂): 325 mMFinal volume (V₂): 925 mL

Step 2: Convert "C₂" to M

We will use the conversion factor 1 M = 1000 mM.

325 mM × (1 M/1000 mM) = 0.325 M

Step 3: Calculate the inital volume

We will use the dilution rule.

C₁ × V₁ = C₂ × V₂

V₁ = C₂ × V₂/C₁

V₁ = 0.325 M × 925 mL/0.792 M

V₁ = 380 mL

3. The presence of the same
a. fossils
b. rocks
on several continents supports the hypothesis of continental drift.
c. neither a norb
d. both a and b

Answers

Answer:

with someone or in the same place as them

Explanation:

If a sample of copper is 215g, how many moles of copper atoms are in the sample?

Answers

Answer:

3.38 moles.

Explanation:

The following data were obtained from the question:

Mass of copper (Cu) = 215 g

Number of mole of copper (Cu) =...?

The number of mole of copper (Cu) in 215 g can be obtained as follow:

Mass of copper (Cu) = 215 g

Molar mass of copper (Cu) = 63.55 g/mol

Number of mole of copper (Cu) =...?

Mole = mass /Molar mass

Mole of Cu = 215/63.55

Mole of Cu = 3.38 moles

Therefore, 3.38 moles of copper (Cu) is present in the sample.

Formula for all possible isomers of hexane​

Answers

Answer:

1) n-Hexane. 2) 2-Methyl pentane(IUPAC name) or Isohexane(common name). 3) 2,2-Dimethylbutane(IUPAC name) or Neohexane(common name). 4) 3-Methylpentane

Explanation:

a student collected data about how different fertilizers affect a plant growth. which type of graph should they use to show the data? PLS HELP ASAP :C worth 100 points lol

Answers

Answer:

I think they should use a bar graph

Explanation:

Because if they use a bar graph they could mark each of the different kind of fertilizer and they could easily see which one affected it the most, either good or bad, by the looking at the heights of the bars to determine your conclusion.

Hi there!

:bar graph:

If they use a bar graph they could mark each of the different kind of fertilizer and they could see easier to tell which one affected it the most, by looking at the heights of the bars to determine the answers.

in one to 2 sentences explain how a stimulus to one type of receptor might be percieved as a simulus to another type of receptor in people who have synesthesia???
HELP

Answers

Synesthetes — or people who have synesthesia — may see sounds, taste words or feel a sensation on their skin when they smell certain scents.

I don't know if this helps at all, but i hope it does.

Help fast I have a few left

Answers

Answer: A

Explanation: 0.00624 x 10^8

All you have to do is move the . 8 units left

This gives you 624000.0

1. Define λmax and explain why it is desirable to do the experimental procedure at λmax? 2. Around what absorbance would you expect the λmax to be with each color solution? (Blue, green, red, yellow) 3. A pipet is used to make the solution dilutions in lab. Suppose in making the dilution, additional distilled water is accidentally added. Will the concentration of the solution be higher or lower that disered? Explain.

Answers

Answer:If you help me with the triple beam balance gizmo then i can do this for you

Explanation:please i need help

Name at least 3 elements used for photographs and cameras .

Answers

Answer:Exposure: Exposure is the basic element of any photograph taken and recorded.

Aperture: Aperture is the setting which controls the size of the opening of light which comes through to the lens.

Shutter Speed: 1Shutter Speed is simply put, the amount of time that the camera lets the light coming in, stay exposed and become recorded.

hope this help!

What do you think is the difference between an "open" system & a "closed" system?

Answers

Answer:

Hope it help you

Stayhomestaysafe

Plz mark my answer brainliest✍️✍️

Explanation:

There are three types of systems in thermodynamics: open, closed, and isolated. An open system can exchange both energy and matter with its surroundings. ... A closed system, on the other hand, can exchange only energy with its surroundings, not matter.

REAL NAME - SHRESTH DUBEY

Can anyone explain to me how I solve 3x10^8 / 3.82x10^-7
I know the answer due to referring to the key but I'm not sure how they got it. Answer was 7.85x10^14

Answers

Answer:

You have to do this on a calculator. So when you put it in the calculator you will get 7.85x10^14.

3x10^8 is the speed of light. 3.82x10^-7 is the number in the question.

You can solve it like this

3x10^8

------------------        

3.82x10^7                  

But you would do this on a calculator.

If a 20-N net force makes an object accelerate at 10 m/s^2, what is the mass of the object?

Answers

Answer:

The answer is 2 kg

Explanation:

The mass of the object can be found by using the formula

[tex]m = \frac{f}{a} \\ [/tex]

where

a is the acceleration

f is the force

From the question we have

[tex]m = \frac{20}{10} \\ [/tex]

We have the final answer as

2 kg

Hope this helps you

The rows in the periodic table are called periods.
What is true about elements in the same period?

Answers

Answer:

elements in the same period have the same number of shells

the period number the element is in, that is the number of shells it has.

Which substances from the simulation are more alkaline than water?
Which

Answers

Answer:

The substances more alkaline than water are;

1) Spit, 2) Blood, 3) Hand Soap, and 4) Drain Cleaner

Explanation:

The diagram in the simulation displays a list of liquid substances, arranged from bottom to top in the order of increasing alkalinity.

The ph of water is 7.0

The ph of spit (saliva) is between 6.2 and 7.6

The ph of blood is about 7.4

The ph of hand soap is between 9 and 10

The ph of drain cleaner is between 12 and 14.

What is the process called when the moon bagins to fade from full moon to new moon

Answers

Waining there’s not much to explain here it’s simple moon phases


Which iron pot has the least thermal energy?
A. A5 kg pot at 130°C
B. A 2 kg pot at 120°C
C. A 5kg pot at 25°C
D. A 2 kg pot at 25°C

Answers

Answer: D. A 2 kg pot at 25C.

Explanation:

5. What is a hypothesis and how is it used?

Answers

Answer: a supposition or proposed explanation made on the basis of limited evidence as a starting point for further investigation.

A hypothesis is used in an experiment to define the relationship between two variables. The purpose of a hypothesis is to find the answer to a question. A formalized hypothesis will force us to think about what results we should look for in an experiment. The first variable is called the independent variable

i hopes this helps :)

state two advantages of parallel over series connection in table form?​

Answers

Advantages of parallel combination over series combination are:

1) In parallel combination each appliance gets the full voltage.

2) If one appliance is switched on/of others are not affected.

3) The parallel circuit divide the current through the appliances. Each appliance gets proper current depending on its resistance.

4) In a parallel combination it is very easy to connect or disconnect a new appliance without affecting the working of other appliances.

choose what you like!

Note that there are also some disadvantages to using parallel connections over series connections, such as increased complexity in wiring and the need for additional safety measures when working with high voltage circuits. The choice between series and parallel connections depends on the specific requirements of the circuit and the devices being used.

- include the process that causes the sun to release so much energy
-The equation for the process that causes the energy. -show what is happening to all the energy coming from the sun.
-how does it affect earth and life on earth

Answers

Answer:   nuclear fusion, equation:(Z + N) in a nucleus of mass M. The formula is B = (Zmp + Nmn − M)c2, All of the energy from the Sun that reaches the Earth arrives as solar radiation, part of a large collection of energy called the electromagnetic radiation spectrum. Solar radiation includes visible light, ultraviolet light, infrared, radio waves, X-rays, and gamma rays. Radiation is one way to transfer heat.

Explanation: i explained everything in the answer hope this helped

which 2 statements describe a mixture?
1. It includes atoms of different elements.
2. Its parts can be separated using physical means.
3. It can result from chemical bonding.
4. It is a pure substance.

Answers

Answer:

It's parts can be separated using physical means.It is a pure substance.

hello~i will really appreciate it if you answer all this♡


1.How many valence electrons do noble gases like Ne,Ar and Kr have?

a.1.
b.2
c.6
d.7

2.The following describe ionic bonding,EXCEPT____.

a.It involves the transfer of electrons.

b.It involves sharing of electrons.

c.atoms either gain or lose electrons.

d.It is a bond between a metal and a non-metal.

3.Which of the following pairs of atoms is most likely to form a covalent compound?

a.C,O
b.Na,O
c.Mg,Br
d.Ba,CI

4.Which of the following is a metal?

a.O
b.S
c.K
d.C

5.Which is not a type of a chemical bonding?

a. Polar bonding
b.Metallic bonding
c.ionic bonding
d.covalent

||. A. Use Lewis structures to show . the transfer of electrons in the given combinations.

1.K +Br
2.Ba + I
3.Be + O
4.Na + S
5.AI + F

B.What ionic charge will the following elements have?PLEASE JUSTIFY YOUR ANSWER.

1. Group 2A
2. Group 5A
3.Group 6A

C.Predict whether the bonding in the oxides of the following elements is covalent or ionic.EXPLAIN YOUR ANSWER.

1.Aluminum
2.Magnesium
3.Phosphorus
4.silicon
5.sodium

|||. Write the electron configuration of the following elements.

1. Ti
2. V
3. Se
4. Ag
5. Zr

thank you!
to your hardwork★

Answers

Explanation:

1)Noble gases have stable valence electron of 2 and 8.

2)B- ionic compounds do not require sharing of electron.

3)B- sodium and oxygen will likely form a covalent compound.

4) C- potassium

5) A- polar bonding

6)

A boy found a solid metal box in his backyard. The box had been buried for so long, it was difficult to determine from what the box was made. The boy measured the box and found its volume (v) to be 17.63 cubic centimeters (cm3) and its mass (m) to be 158 grams (g). The boy knows the formula for density (D) is D = m/v. This table shows the density of several metals. DENSITY OF METALS *

A. copper
B. gold
C. silver
D. tin​

Answers

Answer:

Box is made up of copper, because density is 8.96  g/cm³.

Explanation:

Given data:

Volume of box = 17.63 cm³

Mass of box = 158 g

Which metal box is this = ?

Solution:

First we will calculate the density of box then we will compare it with the density value of given metals.

d = m/v

d = 158 g/ 17.63 cm³

d = 8.96  g/cm³

The calculated density is similar to the given density value of copper thus box is made up of copper.

a screwdriver has a volume of 0.418 cubic centimeters. it also has the mass of 2.3 grams. what is the screwdrivers density

Answers

Answer:

The answer is 5.50 g/cm³

Explanation:

The density of a substance can be found by using the formula

[tex]density = \frac{mass}{volume} \\ [/tex]

From the question we have

[tex]density = \frac{2.3}{0.418} \\ = 5.50239234...[/tex]

We have the final answer as

5.50 g/cm³

Hope this helps you

Answer:

Comets are cosmic snowballs of frozen gases, rock and dust that orbit the Sun. When frozen, they are the size of a small town. When a comet's orbit brings it close to the Sun.

Explanation:

i need help ASAP ! Please

Answers

Answer:

Your friend gave the better response

Explanation:

Formula for density:

Density = mass/volume

p = m/v

Let's substitute the given values into the equation:

p = m/v

p = 23.2/8.593

Solve:

p = 23.2/8.593

p = 2.69987198883

2.69987198883 grams per volume

Notice that 2.69987198883 is the exact answer. Your answer is 2.67, which is inaccurate, even if rounded. If you were to round the exact answer to the nearest hundredth, it would be 2.70 which is not 2.67.

Therefore, your friend gave the better response because it is the correct answer.

density equals mass over volume

23.2/8.593 = 2.69 g/mL

True or false igneous rocks can only turn into metamorphic

Answers

Answer:

this is false igneous rocks can turn into either sedimentary rocks and they can be metamorphic

Explanation:

i hope this helps your welcome :)

Answer:

False

Explanation:

Igneous rocks can turn into sedimentary rocks as well as metamorphic.

can you guys help me please? I dont get what im supposed to do here.

Answers

Oh thats ez its 1M is 1M is 1M is 1M is 1 M

6. In our modern times, the atom can be subdivided into
A.) protons and electrons, only

B.) protons and neutrons, only

C.) protons, neutrons, and electrons, only

D.) neutrons and electrons, only

Answers

Answer:

C.) protons, neutrons, and electrons, only

Explanation:

According to the modern atomic theory, we can distinguish 2 parts in an atom:

The nucleus, where is the majority of the mass of the atom, that is, protons and neutronsThe external shell, where are the electrons.

In a neutral atom, there are the same number of protons (positive charges) as electrons (negative charges).

Which statement best describes how entrepreneurship affects a society's
economy?
A. It encourages people to take risks to create new products.
B. It organizes the people who help a business operate.
C. It provides the raw materials needed to produce goods.
D. It supplies businesses with the tools they need to function.

Answers

i would answer a!

entrepreneurship helps introduce new products and ideas to the economy and encourages other companies to become more competitive. answer a sounds like the most accurate :)

hope this helps!

Answer:it’s a

Explanation:cause

A block weighing 13.15 grams has sides of 11.5 cm, 5.75 cm, and 8.44 cm. What is the density of the block in g/cm?
0.519 g/cm3
0.0236 g/cm3
42.4 g/cm
1.95 g/cm​

Answers

Answer:

B. or .0236

Explanation:

Multiply the 3 sides to get 558.095, then divide the mass and volume to get .0236

Chelsea adds a 65% acid solution to 25 milliliters of a solution that is 30% acid. How much of the 65%
acid solution should be added to create a solution that is 40% acid?

Answers

Answer:

10 ml

Explanation:

The concentration of the acid solution Chelsea adds to the 25 milliliters of 30% acid solution = 65%

The concentration of the acid solution Chelsea requires = 40%

The volume, X, of the 65% acid solution required is given as follows;

65% × X + 30% × 25 = 40% × (25 + X)

As fractions, we have;

0.65 × X + 0.3 × 25 = 0.4 × (25 + X)

0.65·X + 7.5 = 10 + 0.4·X

0.65·X  - 0.4·X = 10 - 7.5

0.25·X = 2.5

X = 2.5/0.25 = 10

X = 10 ml

The volume of the 65% acid that should be added to create a solution that is 40% acid = 10 ml.

Other Questions
Alright repost because i forgot to add the photo and someone reported it. Will mark Brainlyist and please explain how you solved it. How was the French Revolution different than the United States today? If x-1/2y=7 Then 4x-2y=? Use the vocabulary word guerillas in an example sentence. At a concert, Bao sings a song that is very simple. It has one simple melody and no accompaniment. How would a musician BEST categorize her song?lyrical poetrypolyphonicmonophonicorganum What was the name of the island where Cabeza de Vacas barge landed?a.Mauib.Cubac.Malhadod.Jamaica 1. How do you think rapid changes in the chracteristics of habitats affect the niches ofanimals occupying that habitat? PLS HELP!!! ASAP!! 10 POINTS!!Which of the subatomic particles are most responsible for the identity of an element? neutrons electrons atoms protons Jeff bought a bottle of water for $2. He also bought some hot dogs for $3 each. Jeff did not spend more than $14 on the hot dogs and the bottle of water. Which inequality can be used to find h, the number of hot dogs that Jeff could have bought? A.3h214 B.3h+214 C.3h214 D.3h+214 GIVING BRAINLIEST!!! PRETTY SIMPLE QUESTION!!!Mei subscribed to a magazine at a rate of $24 for 12 issues. When she placed her order, Mei used a coupon that added 3 free bonus issues to her subscription. How did the coupon impact the cost per issue of Meis subscription?O The coupon lowered the cost per issue by $0.40.O The coupon lowered the cost per issue by $1.38.O The coupon raised the cost per issue by $0.13.O The coupon raised the cost per issue by $0.67. Cars powered by hydrogen fuel cells emit which substance? For the dilation with center (0,0) shown on the graph, your friend says the scale factor is 5/2 . What is the correct scale factor? What mistake did your friend likely make?Correct answer i know is 2/5, what did the friend do though? here are the choicesA.Your friend found the ratio between non-corresponding sides.B.Your friend found the ratio between two sides of the image triangle.C.Your friend found the scale factor that enlarges to triangle abc to triangle a'b'c'D.Your friend found the ratio between two sides of the original triangle. will Give brainliest What does it mean to plagiarize someone else's work? To add signal words so others know the ideas are yoursTo arrange your work so that it looks like someone else's workTo know how it feels when someone steals your ideaTo use someone else's words or ideas without giving them credit HELP ON NUMBER 5 IMPORTANT how are unit rates and equivalent ratios realted? Choose the sentence that is written with the correct subject-verb agreement.Jennifer love watermelon and strawberries.B.Apple have seeds in their cores.C.The squirrels hide in the trees.D.The kittens drinks the milk. Solve for w.5W + 9 = 22 + 3wOw==-=2Ow== -22W = -2W=-72 Read Abigail Adams letters to her husband and list three reasons she gives about the inequality of women. what is the sum of -8+6 Triangle ABC was transformed to create triangle A'B'C. Which rule best describes this transformation?