13. Which statement best describes an element? *
O any combination of two or more atoms of different types
a pure substance made up of only one kind of atom
O
a substance containing only water molecules
O any kind of crystal

Answers

Answer 1

Explanation:

Distinguish chemical substances from mixtures

Key Points

Matter can be broken down into two categories: pure substances and mixtures. Pure substances are further broken down into elements and compounds. Mixtures are physically combined structures that can be separated into their original components.

A chemical substance is composed of one type of atom or molecule.

A mixture is composed of different types of atoms or molecules that are not chemically bonded.

A heterogeneous mixture is a mixture of two or more chemical substances where the various components can be visually distinguished.

A homogeneous mixture is a type of mixture in which the composition is uniform and every part of the solution has the same properties.

Various separation techniques exist in order to separate matter, including include distillation, filtration, evaporation and chromatography. Matter can be in the same phase or in two different phases for this separation to take place.

Terms

substanceA form of matter that has constant chemical composition and characteristic properties. It is composed of one type of atom or molecule.

elementA chemical substance that is made up of a particular kind of atom and cannot be broken down or transformed by a chemical reaction.

mixtureSomething that consists of diverse, non-bonded elements or molecules.

Answer 2

Answer:

a pure substance made up of only one kind

Explanation:


Related Questions

you have a hypothesis that you can dissolve more sugar in hot water than cold water
what is the independent and dependent variable

Answers

Answer:

The indepandent variable is wether its hot or cold water, so the tempurature of the water. The dependant variable is how much sugar disolves.

Explanation:

The indepandant variable is what changes or has a direct affect on the depandant. The depandant is what is being mesured or tested.

consider three elements A B and C all of which have atomic numbers of less then 20. The atomic number of A is x, and the atomic number of B is three less than the atomic number of A
Element A forms cations with formula A+ and reacts with element C to form a solid substance with the formula AC

What is element A
Which group does element C belong to

Answers

Answer:

LiH

A is lithium

group 1 or 7

A sample of iron has the dimensions of 2 cm x 3 cm x 2 cm. If the mass of this
rectangular-shaped object is 94 g, what is the density of iron?​

Answers

Answer: Volume iron = 2 x 3 x 2 => 12 cm³

Mass = 94 g

D = m / V

D = 94 / 12

D = 7.833 g/cm³

Explanation:

Which metalloid is also a chalcogen?

Answers

Answer:

Oxygen or sulfur I believe since they fall in the same group.

Answer:

Oxygen is one of them.

what is 98.723 m= cm​

Answers

Explanation:

To change from m to cm, divide by 100

[tex] \frac{98.723}{100} \\ = \: 0.98723cm[/tex]

6. Two unknown compounds are tested. Compound I contains 15.0 g of hydrogen and 120.0 g of oxygen. Compound II contains 2.0 g of hydrogen and 32.0 g of oxygen. Are the compounds the same?

Answers

Answer:they are not the same because the composition differ

Explanation:

*
6. "The mixture is green in color." This confirms that the mixture is a

Answers

The question is incomplete, so the complete question is as follows:

"The mixture is green in color.” This confirms that the mixture is a.

A) suspension B) solution C) colloid D) this proves nothing

Answer:

D) this proves nothing

Explanation:

The green-colored mixture does not prove anything about the mixture because only the color of mixture can not decide the typw of mixture.

Several other properties affecting the type of mixture are the size of particles and also dispersion of particles in the solution.

Hence, the correct answer is "D",

please help me with this!

Answers

Answer:

4.76 × 10¯⁵ cm

Explanation:

The conversion of 476 nm to cm can be obtained as follow:

1. Conversion of 476 nm to m

Recall

1 nm = 1 × 10¯⁹ m

Therefore,

476 nm = 476 × 1 × 10¯⁹ = 476 × 10¯⁹ m

2. Conversion of 476 × 10¯⁹ m to cm

Recall:

1 m = 100 cm

Therefore,

476 × 10¯⁹ m = 476 × 10¯⁹ × 100

476 × 10¯⁹ m = 476 × 10¯⁷ cm

476 × 10¯⁹ m = 4.76 × 10¯⁵ cm

Therefore,

476 nm is equivalent to the 4.76 × 10¯⁵ cm

Why is calcium chloride (rock salt, CaCl2) more effective than sodium chloride (table salt, NaCl) at de-icing roads in the winter? A. Calcium chloride only breaks into 2 ions, while sodium chloride does not break up and remains 1 ion. B. Calcium is a larger molecule than sodium, so it has a greater effect. C. The additional chlorine atom forms a stronger bond between the atoms in calcium chloride than in sodium chloride, so calcium chloride remains one molecule while sodium chloride breaks apart. D. Calcium chloride breaks into 3 ions, while sodium chloride only breaks into 2 ions.

Answers

Answer:

The correct option is;

D. Calcium chloride breaks into 3 ions, while sodium chloride only breaks into 2 ions

Explanation:

To help melt the ice on icy streets, calcium chloride (CaCl₂) is a more preferred salt type to sodium chloride (NaCl) as when it dissociates into ions in the ice, it forms three ions: a calcium ion, Ca²⁺, and two chloride ions, 2 Cl⁻, while sodium chloride forms two ions: one sodium ion, Na⁺, and one chloride ion, Cl⁻

According to the freezing point depression equation, we have;

ΔT = [tex]K_f[/tex] × m × i

Where;

ΔT = Change in freezing point temperature

[tex]K_f[/tex] = The freezing point depression constant

m = The solution's molality

i = van't Hoff factor

The calcium chloride salt will cause the most depression because the van't Hoff factor is 3 for calcium chloride and 2 for sodium chloride.

Answer:

d im pretty sure i got the same answer

Explanation:

Balance the following equations: i) KClO3 KCl + O2 ii) HNO3 + NaHCO3 NaNO3 + H2O + CO2 iii) Na + H2O NaOH + H2

Answers

i) 2KClO3 → 2KCL + 3O2

ii) HNO3 + NaHCO3 → H20 + CO2

iii) 2Na + 2H2O → 2NaOH + H2

how does getting funding from the government affect scientific research?? a- the government helps the scientist decide what research is important b- the government tells the scientist what research they can do c-scientist can only do research that helps the government protect its citizens d- scientist have to follow government rules made to protect people

Answers

Answer:

d- Scientists have to follow government rules made to protect people.

Explanation:

Scientific research fosters our understanding of the world around us. It helps people to learn to promote critical thought and problem-solving.  Although there may not be an immediate practical use of the research, in the long term the study could benefit humanity. Scientific research is the product of creative ideas and collaborative communication that the proper role of government is often restricted to funding the research. The role of the government is to perform its reasonable and valid duties of defending human rights and enhancing the independence of the human.

Answer:D

Explanation:

If an atom has 16 protons, 14 neutrons, and 18 electrons. What is the charge of the nucleus?

Answers

Answer:

The charge of nucleus will be +2.

Explanation:

Given that,

Proton = 16

Neutron = 14

electron = 18

We know that,

Atomic number :

The number of proton in the nucleus is equal to the atomic number.

The number of protons is equal to the number of electrons for neutral atom.

So, the atomic number is same as the number of electrons.

Here, the number of electron is more than 2 of number of proton.

Hence, The charge of nucleus will be +2.


Round your answer to the correct number of significant figures or decimal places: 0.005-0.0007=

Answers

Answer:

0.0043

0.004 if to one significant figure

0 to one decimal place.

In the same science fair, Tina asks the question "Does caffeine increase the heart rate of an earthworm?" In Test 1, she measures the heart rate by looking at the earthworm under a microscope, the earthworm has a heart rate of 50 bpm (beats per minute). In Test 2, she places a few drops of caffeine on the earthworm's skin and measures the rate again. In this test, the heart rate is 68 bpm. 6) What is the Independent/Manipulated variable? 7) What is the Dependent/Responding variable? 8) Tina's experiment should have included a hypothesis. In a complete sentence, suggest a hypothesis for Tina's experiment. You may use an if/then statement.

Answers

Answer:

Independent variable- effect of caffeine

Dependent variable- heart rate

Hypothesis- If a stimulant such as caffeine is administered to earthworm, then its heart rate increases.

Explanation:

The experiment is based on the research question; "Does caffeine increase the heart rate of an earthworm?" We can see from this research question that the independent variable is the effect of caffeine and the response it produces is a change in the heart rate (the dependent variable)

This now leads us to a hypothesis that states thus; 'If a stimulant such as caffeine is administered to earthworm, then its heart rate increases.'

The solubility of KNO3 is 32g/100g of water at 20oC and 62g/100g of water at 40oC. What will you observe if a saturated solution of KNO3 at 400C is cooled to 20oC.

Answers

Answer:

Explanation:

Solubility of KNO₃ at 20° C = 32 g / 100g of water

that means , per 100 g of water maximum of 32 g of  KNO₃ can be dissolved at 20° C .

Solubility of KNO₃ at 40° C = 62 g / 100g of water

that means , per 100 g of water maximum of 62 g of  KNO₃ can be dissolved

40° C.

So when a saturated solution in which maximum KNO₃ has been dissolved is cooled from  40° C to 20° C , due to decrease in solubility at lower temperature some KNO₃ will come out of the solution . Per 100 gram of saturated solution , 62 - 32 = 30 g of KNO₃ will precipitate out or come out of water . They can be filtered out .

In stomach, Hydrochloric acid kills micro-organisms in the food. Stomach juices begin to break down p to amino acids. Stomach juices begin to break down p____________ to amino acids. please answerr <3333

Answers

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Inside the stomach, Hydrochloric acid kills micro-organisms in the food. Stomach juices begin to break down proteins to amino acids.

✤ So, Fill the blank with proteins.

Explanation:-Inside the stomach, the digestion of proteins starts due to the action of pepsin enzyme.But this enzyme remains inactive and is activated by the Hydrochloric acid(HCl).The Hydrochloric acid also helps in killing the germs and microbes which entered along with food.The mucous lines the wall of stomach to protect it from the harm caused by HCl because HCl is a strong acid.In stomach, The partial digestion of proteins occur and rest is digested in the small intestine by Trypsin(Pancreatic enzyme) and Intestinal juices.

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pls help
will give the brainliest!
pls answer correctly
Urgent!!!​

Answers

Answer:

Explanation:

reaction A is an acid base reaction

here MgO  is base and H2SO4  is an acid

reaction B is an acid base reaction

here CO3^-² is  weak base and H+ is an acid

reaction D is an acid base reaction water is amphoteric in nature here it behave like base and HCL is an acid

reaction F is acid base reaction

here NH3 is an base  and HCL  is an acid

reaction G is acid base reaction

here NaOH is base and HCL is an acid

in reaction c and e Al is hard acid and Cu is soft acid and HCL is acid and Zn is base but i m not confirmed that these reactions are acid base or not

A clock gains 0.020 seconds per minute. How many seconds will the clock gain in exactly 6 months, assuming exactly 30 days per month? (Chemistry)

Answers

Answer: 5184.000 seconds

Explanation:

If there are 30 days per month then we are trying to find how many seconds the clock will gain in 180 days (30*6). If the clock gains 0.020 seconds per minute, then it gains 28.800 seconds per day (0.020*60*24). We can then multiply this by 180 days to get 5184.000 seconds.

If A • B*2 = 1.8 x 10*-7, and C•B/D = 7.2 x 10*-4, find the value of A•D*2/C*2

Answers

Answer:

A*D²/C² = 0.347

Explanation:

A*B² = 1.8*10⁻⁷----- (1)

making A subject of formula; A = 1.8 * 10⁻⁷/B² ----(2)

C* B/D = 7.2*10⁻⁴ ----(3)

making C subject of formula; C = D * 7.2*10⁻⁴/B ----(4)

substituting the values of A and C in the equation A*D²/C²

A*D²/C² = (D² * 1.8 * 10⁻⁷/B²)/(D * 7.2*10⁻⁴/B)²

A*D²/C² = (D² * 1.8 * 10⁻⁷/B²)/(D² * 5.184*10⁻⁷/B²)

A*D²/C² = D² * 1.8 * 10⁻⁷/B² * B²/D² * 5.184*10⁻⁷

A*D²/C² = 1.8 * 10⁻⁷/5.184*10⁻⁷

A*D²/C² = 0.347

is solar energy ecosystem services if so why

Answers

yes

Explanation

it is using the sun energy as an energy resource and is therefore Eco friendly

Hope this answer correct :)

Is sodium ion or sodium metal in table salt?

Answers

Answer:

sodium ion

Explanation:

Which of the following is displaced by 'Cu'? 1.Fe2+ 2.Ag+ 3.Zn2+ 4.Al3+

Answers

Answer:

2.Ag+

Explanation:

This problem tests our knowledge/understanding of the electro-chemical series.

Electrochemical series or activity series is a list that describes the arrangement of elements in order of their increasing electrode potential values.

In the electro-chemical series metals placed above can displace metals below from their salt solutions.

In this question given the series as  stated

1. Fe2+

2.Ag+

3.Zn2+

4.Al3+  

In the series we have metals stated as Zn>Fe>Cu>Ag.

Cu will displace silver Ag+  because it is below it in the series

Introduction of transition metals? (one big paragraph please)​

Answers

Answer:

its answer this question q1

Identify the terms described by selecting the correct word from the drop-down menu.
Anything that has mass and takes up space
The part of Earth in which life exists, including land, water, and air

Answers

Answer: Matter

Biosphere

Explanation:

The substance that occupies space and mass is called matter, and the biosphere is the part of the earth that includes life. Thus, the correct options are 1. c and 2. b.

What is the matter?

A matter has been defined as a substance that is made of atoms and has a mass that results in it occupying some space. The matter can be in the form of liquid, solids, or gas. The matter is present everywhere and can be interconnected. Thus, 1. c is correct.

The biosphere is defined as the sphere that combinedly comprises the hydrosphere, lithosphere, and atmosphere and is the part where life exists on the earth. It includes the elements air, water, land, etc., and all the ecosystems that range from oceans to mountains. Thus, 2. b is correct.

Therefore, options 1. c. matter and 2. b. the biosphere is correct.

Learn more about the matter, here:

https://brainly.com/question/9402776

#SPJ2

Your question is incomplete, but most probably your full question was,

1. Anything that has mass and takes up space

AtomElementMatter

2. The part of the earth in which life exists including land water and air

ThermosphereBiosphereExosphere

Which statement correctly describes a scientific theory? A. It is accepted as true indefinitely. B. It is based on repeated investigations. C. It is equivalent to a scientific law. D. It is accepted as false.

Answers

The correct answer is B

Match the name of each gas law to the properties it compares. Boyle's law Charles's lawGay-Lussac's lawA) Pressure and volume B) Temperature and volume C) Pressure and temperature

Answers

Answer:

Boyle's law: A) Pressure and volume.

Charles's law: B) Temperature and volume.

Gay-Lussac's law: C) Pressure and temperature.

Explanation:

Hello,

In this case, since Boyle's law study the relationship between pressure and volume at constant temperature as an inversely proportional one, we have:

Boyle's law: A) Pressure and volume.

Next, since the Charles' law study the relationship between the volume and the temperature at constant pressure as a directly proportional one, we have:

Charles's law: B) Temperature and volume.

Then, since the Gay-Lussac's law study the relationship between the pressure and the temperature at constant volume as a directly proportional one as well, we have:

Gay-Lussac's law: C) Pressure and temperature.

Best regards.

Answer:

D, B, E

Explanation:

How are the steps you went through when discovering a new species similar to the steps of the scientific method? Were any steps skipped?

Answers

Answer:

Most steps were skipped they couldn't predict what it would be they couldn't really observe I font think they used very many.

The current day periodic table is organized by

Answers

Answer:

Dmitri Mendeleev

Explanation:

Dmitri Mendeleev published the first recognizable periodic table in 1869, developed mainly to illustrate periodic trends of the then-known elements. He also predicted some properties of unidentified elements that were expected to fill gaps within the table. Most of his forecasts proved to be correct

Answer:

Mendeleev periodic table

Explanation:

In 1869, just five years after John Newlands put forward his

Law of Octaves, a Russian chemist called Dmitri Mendeleev

published a periodic table. Mendeleev also arranged the

elements known at the time in order of relative atomic mass

A scientist wants to find the percent of teens that like the taste of "brand X" lemonade over "brand Y" lemonade. She conducts a taste test of 500 teenagers. She gives each teen a bottle of lemonade with the labels showing the brand of each lemonade. She asks each teenager to taste each brand after drinking water in between. She finds that 50% of teens like brand X and 50% like brand Y lemonade. Why are the results of the survey most likely unreliable?

Answers

Answer:

She gave them bottles with labels showing the brands

Explanation:

the teens could have been biased due to knowing the brand. It would have been more reliable if the label was covered or removed.

can you help me what is the arrhenius concept of acid and bases explain in detail

Answers

Answer:

Explanation:

The Arrhenius definition of acid-base reactions, which was devised by Svante Arrhenius, is a development of the hydrogen theory of acids. It was used to provide a modern definition of acids and bases, and followed from Arrhenius’s work with Friedrich Wilhelm Ostwald in establishing the presence of ions in aqueous solution in 1884. This led to Arrhenius receiving the Nobel Prize in Chemistry in 1903.

As defined by Arrhenius:

An Arrhenius acid is a substance that dissociates in water to form hydrogen ions (H + ). In other words, an acid increases the concentration of H + ions in an aqueous solution. This protonation of water yields the hydronium ion (H 3 O + ); in modern times, H + is used as a shorthand for H 3 O + because it is now known that a bare proton (H + ) does not exist as a free species in aqueous solution.

An Arrhenius base is a substance that dissociates in water to form hydroxide (OH – ) ions. In other words, a base increases the concentration of OH – ions in an aqueous solution.

Other Questions
Timberly Construction negotiates a lump-sum purchase of several assets from a company that is going out of business. The purchase is completed on January 1, 2015, at a total cash price of $820,000 for a building, land, land improvements, and four vehicles. The estimated market values of the assets are building, $492,900; land, $260,400; land improvements, $55,800; and four vehicles, $120,900. The companys fiscal year ends on December 31. Required: 1.1 Prepare a table to allocate the lump-sum purchase price to the separate assets purchased. 1.2 Prepare the journal entry to record the purchase. 2. Compute the depreciation expense for year 2015 on the building using the straight-line method, assuming a 15-year life and a $32,000 salvage value. (Round your answers to the nearest whole dollar.) 3. Compute the depreciation expense for year 2015 on the land improvements assuming a five-year life and double-declining-balance depreciation. 1.1 Prepare a table to allocate the lump-sum purchase price to the separate assets purchased. 1.2 Prepare the journal entry to record the purchase. 2. Compute the depreciation expense for year 2015 on the building using the straight-line method, assuming a 15-year life and a $32,000 salvage value. (Round your answers to the nearest whole dollar.) 3. Compute the depreciation expense for year 2015 on the land improvements assuming a five-year life and double-declining-balance depreciation. Help! Please simplify: 0.2(3a1)+0.30.6 Thank you! Which sentence from the passage uses a verb in the passive voice?A. He had gone to Kentucky to help free slaves. (paragraph 1)BRutherford B. Hayes had a law office there, and aftermeeting Lucy, he visited the Webb home often (paragraph3).After the war, her husband became governor of Ohio.(paragraph 5)D. In 1877, Rutherford B. Hayes was confirmed as thenineteenth president of the United States. (paragraph 6) you recently finished an essay on the milky way galaxy in google docs, but you cant locate the file anywhere on your Google Drive. What should you do? please help Which is one step that geologists use to find the epicenter of an earthquake? A: They look at data from at least one seismograph. B: They measure the difference between arrival of P waves and S waves. C: They draw circles around the epicenter from three locations. D: They obtain information about the intensity of earthquakes from seismographs. What is the answer to the main problem If mJKM = 43, mMKL = (8 - 20), and mJKL = (10x - 11), find each measure.1. x = ?2. mMKL = ?3. mDEF = ? In this unit, you learned about the development of the world's first great civilizations. What traits did these civilizations have in common? In what ways did they differ? Do you think there are certain traits or conditions that were necessary for the development of these civilizations? Why? Helen is considering adding a rack of greeting cards to her product offerings at Litton Books Unlimited. Her fixed costs associated with adding the greeting cards would be $300. Variable costs per card are $1 each. The greeting cards will sell for $2 each. Helen's break-even point would occur at ________ cards sold. Please help me, what I need help on is in the picture. (Geometry) The purpose of the best-fit line on an experimental scatterplot is to:_______. a. The best-fit line allows us to predict behavior between measured data using its slope. b. Ignore data points that don't fit the line. c. Determine individual slopes between each set of data points (Image) Use Pythagorean Theorem to find the length of the missing side of this right triangle to the nearest tenth. can u help me i cant solve Overfishing of salmon has caused populations of wild salmon to decline. To combat this decline, salmon are raised in hatcheries, and then released to the wild. However, researchers have found that hatchery-raised salmon have reduced reproductive success in the wild, compared to wild salmon. They have also identified many genetic differences between hatchery-raised and wild salmon. 4v25>2v+17 f(x) = --3find f(-4) The last four years of returns for a stock are as follows: Year 1 2 3 4 Return 4.5% 28.1% 12.2% 3.7% a. What is the average annual return? b. What is the variance of the stock's returns? c. What is the standard deviation of the stock's returns? Which coordinates provide the location for the city of New Orleans? A student goes into Amazon to purchase a biology textbook that was published by McGraw-Hill Higher Education and then sold to Amazon through a book wholesaler. In this marketing channel, Amazon would best be classified as a What biological macromolecule is made up of monomers like the one shown below? A. Lipid B. Nucleic acid C. Protein D. Carbohydrate