which physical change is endothermic
Answer:The physical changes that are endothermic are melting, vaporization and sublimation.
Explanation:
Calculate the number of moles in 11.0 grams of NaOH . Please show your work to receive credit.
Answer: 0.275 moles
Explanation: Na- 22.99g (on periodic table)
O- 16g and H- 1.01
22.99 + 16 + 1.01 = 40g/mol of NaOH
11g of NaOH / 40g / mol of NaOH = 0.275mol NaOH
What is the weight of 12.0 moles of water?
Answer:
216g H2O
Explanation:
H = 1
O = 16
H= 2 × 1 = 2
O= 1 × 16 = 16
16 + 2= 18g/mol
18g H2O = 1 mol
X g H2O = 12 mol
X × 1 = 18 × 12
X = 216 g/mol
The weight of 12.0 moles of water is determined as 216 g.
What is the weight of the water?The weight of water is determined from the molecular weight of water. The molecular weight of water is given 18 g/mol.
The weight of 12 moles of water is calculated as follows;.
W = nM
W = 12mole x 18 g/mol
W = 216 g
Thus, the weight of 12.0 moles of water is determined as 216 g.
Learn more about weight here: https://brainly.com/question/2337612
#SPJ2
Most of the dissolved substance in sea water is: hydrogen chloride nitrogen sodium ANSWER NOW! I NEED HELP ASAP! WILL GIVE BRAINLIEST!
Answer: Sodium chloride
Explanation:
Ocean water contains a number of substances. When a substance which has ionic bonds is dissolved in water it takes the form of ions.
The most common ions in ocean water are sodium and chloride. These are the ions formed when common salt, sodium chloride (NaCl) is dissolved in water.
Sodium chloride accounts for about 3% of ocean water by mass.
Answer:
By far, the most abundant elements are hydrogen and water.
Explanation:
The analysis of the 77 sea water samples taken during the Challenger's 3-year voyage did much to lay the foundations for determining the chemical content of sea water. By far, the most abundant elements are hydrogen and water (combined to make water). Together, these elements make up 96% of sea water. Sodium chloride and magnesium make up just under 4% of sea water. Trace amounts of 97 other elements are found in the remaining 0.08%. Of the trace elements, calcium, potassium, sulfur, and bromine are the most abundant.
This is directly from the text.
Someone help me plz I’ll give u BRAINLIEST!! I’ll really appreciate for ur help I suck at writing essay’s PLZ PLZ!!!!
Answer:
i cant see what it says
Explanation:
OUTLINE
Paragraph 1: Introduction
Paragraph 2: Body Paragraph
Paragraph 3: Body Paragraph
Paragraph 4: Body Paragraph
Paragraph 5: Conclusion
Think of the introduction and conclusion as “bookends” that serve to hold the essay tightly together. The
introduction will “push” into or initiate the examination of your topic and the angle you decide to focus on, while
the conclusion will “pull” tight all the ideas that you have gathered together for a unified essay.
Remember, the five-paragraph model can be expanded to include more body paragraphs that probe more deeply
into your subject. Check with your instructor to ensure whether or not you can exceed this length for an
assignment.
The introductory paragraph should include the following elements:
Background information: Enough information necessary for your reader to understand your topic
Thesis statement: Indicates your paper’s topic, makes your paper’s purpose clear, and provides an
overview of the three main supporting points that will unify the essay. The thesis statement is typically
the last sentence.
If you are writing in response to a text, the introduction should include the title, author, and genre of that
piece.
Begins with a topic sentence that identifies one main idea that will be discussed as support or proof for the
thesis statement
Supporting sentences use specific details, demonstrated through closely related examples or evidence, to
expand and explain the main idea. Generally, a well-developed paragraph has at least five to eight
sentences.
Paragraph unity means that all ideas in a paragraph are closely related to its topic sentence and further
develop that topic sentence. That is, all sentences in a single paragraph must be unified around a central
point or idea.
This paragraph, and any subsequent body paragraph, should begin with a topic sentence that signals the
reader that a new idea or point is being introduced.
As you organize your essay, keep in mind its coherence. Coherence refers to connections among
paragraphs and ideas—the logical sequence of your thoughts.
o Use transition words or phrases at the outset of your body paragraphs and to move from one idea
to another within your paragraphs.
o Have you transitioned logically from the main idea in the previous paragraph to this one? Are you
making clear connections among the paragraphs and ideas? Be sure to think about coherence during
the revision stage of the writing process.
This paragraph begins with the final topic sentence that relates back to the remaining point mentioned in the
thesis statement. Each paragraph should contain a new main idea.
Again, flesh out this main idea with specific examples, details, and relevant support.
Be sure to maintain paragraph unity. That is, each sentence must relate to your topic sentence.
The conclusion revisits your overall purpose for writing and often invites your reader to consider the
implications of why your ideas are significant.
The conclusion may restate the thesis, summarize the paper’s major points, or leave the reader with a final
thought to ponder. Several other methods for writing conclusions are included on a separate Tutoring Center
handout. If you choose to restate the thesis or summarize the essay’s main ideas, do not repeat the same
wording from the introduction or body paragraphs. Remember not to introduce new, unrelated ideas in the
conclusion
What’s the difference between Fe and Fe2+?
Fe is the pure element (Iron) while Fe2+ is an isotope of Fe.
Stereoisomers share the same connectivity and differ only in the way their atoms are arranged in space. Draw the structure of a compound that is a stereoisomer of trans-1,2-dibromocyclobutane.(Note that the question asks for a different stereoisomer of the named compound and not the named compound itself.)Use the wedge/hash bond tools to indicate stereochemistry.Show stereochemistry in a meso compound.In cases where there is more than one answer, just draw one. (use same instructions below)
1b) Draw the structure of a compound that is a stereoisomer of cis-1,2-dimethylcyclopentane.1c) Draw the structure of a compound that is a stereoisomer of cis-1,2-dimethylcyclobutane.
Answer:
Explanation:
A stereoisomer refers to an isomer that shares an identical bonding structure but differs in the geometric position of functional groups and atoms.
Stereoisomers are molecules which have the same semi-expanded formula, but a different arrangement in space.
They are isomers with a similar structural formula, yet which contrast just in their spatial geometry.
From the given question, we are provided with some set of instructions to draw the structure of the following compounds.
stereoisomer of trans-1,2-dibromocyclobutane
cis-1,2-dimethylcyclopentane
cis-1,2-dimethylcyclobutane
The diagram for each compound given can be seen in the attached file below.
At STP, a 50-gram sample of H20(I) and a 100-gram sample of H20(I) have
Answer:
(1) the same chemical properties .
Explanation:
Hello!
In this case, among the options:
(1) the same chemical properties
(2) the same volume
(3) different temperatures
(4) different empirical formulas
We can see that they have the same chemical properties as they at the same conditions, same type of bond (polar), molecular geometry, bond angle (104.5 °) and so on. Nevertheless, at STP (1 atm and 273.15 K) they do not have the same volume since the larger the mass, the larger the volume, they have the same temperature and the both of them are H₂O.
It means that the answer is (1) the same chemical properties .
Best regards.
which metal is most likely to form more than one kind of positively charged ion
Answer:
metal atoms lose electrons to form positivity charged ions. non metal atoms gain electrons to form negatively charged ions
How many gases are there that are not noble gases
Answer:
Noble gas, any of the seven chemical elements that make up Group 18 (VIIIa) of the periodic table. The elements are helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), radon (Rn), and oganesson (Og).
Explanation:
I pretty much covered it in my answer!
Pls Brainliest! It would mean a lot! ;)
What are the basic building blocks of proteins?
OA
starches
OB. electrolytes
Ос.
amino acids
OD
polyunsaturated fats
Answer:
Amino Acids
Explanation:
What Are Proteins Made Of? The building blocks of proteins are amino acids, which are small organic molecules that consist of an alpha (central) carbon atom linked to an amino group, a carboxyl group, a hydrogen atom, and a variable component called a side chain.
Answer:
Amino Acids
Explanation:
An object that is 0.5 m above the ground has the same
amount of potential energy as a spring that is stretched
0.5 m. Each distance is then doubled.
How will the potential energies of the object and the
spring compare after the distances are doubled?
O The gravitational potential energy of the object will
be two times greater than the elastic potential energy
of the spring.
O The elastic potential energy of the spring will be four
times greater than the gravitational potential energy
of the object.
The elastic potential energy of the spring will be two
times greater than the gravitational potential energy
of the object
O The potential energies will remain equal to one
another
The elastic potential energy of the spring will be two times greater than the gravitational potential energy of the object.
Answer:
C.) The elastic potential energy of the spring will be two times greater than the gravitational potential energy of the object.
Explanation:
Hope this helps! Sorry if I am wrong. ;-;
Molecules such as water that are electrically neutral overall but still have partially charged regions are referred to as?
A. Covalently charged
B. Ions
C. Electrolytes
D. Isotopes
E. Polar molecules
Answer:
B
Explanation:
I studied this and had a test
What causes the emission of light?
Answer:
When the electrons in the atom are excited, for example by being heated, the additional energy pushes the electrons to higher energy orbitals. When the electrons fall back down and leave the excited state, energy is re-emitted in the form of a photon. The wavelength (or equivalently, frequency) of the photon is determined by the difference in energy between the two states. These emitted photons form the element's spectrum.
The fact that only certain colors appear in an element's atomic emission spectrum means that only certain frequencies of light are emitted. Each of these frequencies are related to energy by the formula:
{\displaystyle E_{\text{photon}}=h\nu }E_{\text{photon}}=h\nu ,
where {\displaystyle E_{\text{photon}}}E_{\text{photon}} is the energy of the photon, {\displaystyle \nu }\nu is its frequency, and {\displaystyle h}h is Planck's constant. This concludes that only photons with specific energies are emitted by the atom. The principle of the atomic emission spectrum explains the varied colors in neon signs, as well as chemical flame test results (described below).
The frequencies of light that an atom can emit are dependent on states the electrons can be in. When excited, an electron moves to a higher energy level or orbital. When the electron falls back to its ground level the light is emitted.
Explanation:
Determine a piece of copper with a volume of 100 cm power 3 has a mass of 890 g. Explain how you could use this information to find out how much mass would be in 13 cm power 3 of copper
Elements in the same period of the periodic table exhibit similar physical and chemical properties.
Answer:
same valency electrons
Explanation:
example g 1 elements
A Geiger counter used in several applications over the course of a typical day produces on the average 100 counts per second. The tube is in the form of a cylinder 5 cm in diameter by 20 cm long and is filled with a mixture of 90% argon and 10% ethanol to a pressure of 0.1 atmosphere. In the Geiger-Muller region, each output count results from the formation of about 1010 ion-electron pairs. How long will it take for one-third of the quenching gas to be used up, thus necessitating replacement of the tube
Answer:
As it is given that
[tex]activity=\lambda= 100\\[/tex]
[tex]Number~of ~counts=100/second\\[/tex]
Using formula
[tex]ln(\frac{N}{N_o})=-\lambda\cdot t\\\\[/tex]
or
[tex]-\frac{ln(\frac{N}{N_o})}{\lambda}= t\\\\[/tex]
where [tex]N=\frac{N_o}{3}[/tex]
[tex]-\frac{ln(\frac{1}{3})}{100}= t\\\\\-\frac{-1.0986}{100}=t\\\\[/tex]
[tex]\frac{1.0986}{100}=t\\1.0986\cdot 10^{-2}seconds=t\\[/tex]
Which of the following is TRUE?
A. Lipids are fatty substances found in the blood.
B. Cholesterol is a type of lipid.
C. Triglycerides is a type of lipid.
D. All of the above
Answer:
The answer is D.
Explanation:
I learned about this last year. Its very simple if you let your parents or teachers explain it to you!
Answer:
All of the above
Explanation:
All the answers are correct. Lipids come in difference forms.
The table shows the average number of pounds of trash generated per person per day in the United States from 1970 to 2010. Use the statistics calculator to calculate the mean and median. Round the answers to the nearest hundredth.
Median =
Mean =
Answer: median :4.44 mean :4.11
Explanation:
i did test on Edge
A pitcher throws a 142 g baseball, which accelerates at a speed of 9 m/s^2. How much force does the pitcher apply to the ball?
Answer:
The answer is 1.28 NExplanation:
The force acting on an object given the mass and acceleration we use the formula
force = mass × accelerationFrom the question
mass = 142 g = 0.142 kg
acceleration = 9 m/s²
We have
force = 0.142 × 9 = 1.278
We have the final answer as
1.28 NHope this helps you
Answer:
1.28
Explanation:
In order for you to get the force you have to multiply the mass & acceleration. The baseball mass is 142 g and the acceleration is 9. So you will calculate 0.142 x 9 and that will give you 1.278. You will then round the 7 to an 8 and then you get the answer 1.28.
Stomach acid is predominately hydrochloric acid. Write the balanced chemical equation for the neutralization reaction between HCI and the active ingredient.
Express your answer as a chemical equation. Identify all of the phases in your answer
Answer:
HCl + Mg(OH2) ---> MgCl2 + H2O
Explanation:
hydrochloric acid + magnesium hydroxides ==> magnesium Chloride (a salt) + Water
HCl + Mg(OH2) ---> MgCl2 + H2O
Wich of the following does not directly affect the weather
Answer:
Tings that effect weather is basically the following:
Distance from seaAltitudeDistance to the equator or poles.MountainsJet streams,etcEukaryotes share which characteristic with prokaryotes?
•lysosomes
•vacuole
•mitochondria
•cell membrane
Answer:
cell membrane is the answer
Answer: cell membrane
Explanation:
Translate each number into standard notation
4.52 x 10 power3
Answer:
4.52×1000=4520
Explanation:
4.52*1000=4520
Is this a model of an element, a compound, or a mixture? Explain your reasoning.
Answer:
A mixture.
Explanation:
The image contains two types of molecules: one with a blue centre and one with a green centre. They are both compounds, as they contain atoms of different elements that are chemically combined/ bonded to each other. As the molecules of the different compounds are not bonded to each other, the model must show a mixture.
A mixture: a combination of molecules of different elements and/or compounds that are not chemically combined e.g. salt dissolved in water.
An element: a substance containing only one kind of atom e.g. oxygen.
A compound: a substance containing two or more kinds of atoms (atoms of different elements) are chemically bonded to each other e.g. water.
In the model of an element, it represents a mixture. The correct option is b.
What is a mixture?A mixture is a non-chemically coupled combination of molecules from different elements and/or compounds, such as salt dissolved in water.
There are two kinds of molecules in the image: one with a blue center and one with a green center. They are both compounds because they contain atoms of different elements that have been chemically combined/bonded. Because the molecules of the various compounds are not bound to one another, the model must depict a mixture.
A compound is a substance that contains two or more types of atoms (atoms of different elements) that are chemically bound to one another, such as water.
Therefore, the model shows a mixture.
To learn more about mixture, refer to the link:
https://brainly.com/question/24898889
#SPJ2
Which option(s) correctly shows an anion? Select all that apply.
Answer:
x
Explanation:
becaue neutron equal to mass num -atomic num
Ai +O2 =Ai2O3 how many atoms of oxygen exist in this product
Calculate the molarity of a solution prepared by dissolving 0.20 mol of KNO3 into enough water to make 250 mL of solution. ______ M
Answer:
0.8M
Explanation:
Given parameters:
Number of moles of KNO₃ = 0.2mol
Volume of KNO₃ = 250mL
Unknown:
Molarity of the solution = ?
Solution:
The molarity of a solution is the number of moles in a given volume of a solution;
Molarity = [tex]\frac{number of moles }{volume}[/tex]
We need to convert the given volume to L;
1000mL = 1L
250mL will give 250 x 10⁻³L = 0.25L
So;
Molarity = [tex]\frac{0.2}{0.25}[/tex] = 0.8M
Answer:
0.8 M
Explanation:
The formula is mol divided by liters. Converting 250 ml to .25 liters is important. Dividing .2 by .25 gets the answer. (I swear it’s right but it’s graded wrong so take this with a grain of salt)
Please help i don’t understand
the difference between a molecule and a compound is that a compound is made up of atom from
Answer:
answer explained below.
Explanation:
hey! a molecule is made up of two or more atoms, and a compound is made up of two or more elements. not all molecules are compounds, but all compounds are molecules, because compounds are made up of different atoms.
example: O2 is a molecule but not a compound because it is made up of the same element, but has more than one atom.