Answer: b. False
Explanation:
The more energetic molecules move to a gas, spread out, and form bubbles when heating happens. When exposed to heat, many of the chemicals used in the laboratory are volatile and harmful (fire).
So leaving a material that you heat for even a second can be very hazardous and negligent.
number of electrons in 21Sc with L=1
Answer:
There are [tex]12[/tex] electrons with [tex]l = 1[/tex] in each [tex]\rm _{21}Sc[/tex] atom in its ground state.
Explanation:
The azimuthal quantum number (with symbol [tex]l[/tex]) of an electron in an atom specifies the type of the orbital that contains this electron.
For example:
[tex]l = 0[/tex] corresponds to an [tex]s[/tex] orbital.[tex]l = 1[/tex] corresponds to a [tex]p[/tex] orbital.[tex]l = 2[/tex] corresponds to a [tex]d[/tex] orbital.The question is asking for the number of electrons with [tex]l = 1[/tex] in each [tex]\rm _{21}Sc[/tex] atom. Because [tex]l = 1\![/tex] corresponds to [tex]p[/tex] orbitals, this question is equivalently asking for the number of electrons in [tex]p\![/tex] orbitals in one such atom.
Find the electron configuration of a ground-state [tex]\rm _{21}Sc[/tex] atom:
[tex]1s^{2}\; 2s^{2}\; 2p^{6}\; 3\, s^{2}\; 3\, p^{6}\; 3d^{1}\; 4s^{2}[/tex].
In other words, there are [tex]12[/tex] electrons in [tex]p[/tex] orbitals in total in a ground-state [tex]\rm _{21}Sc[/tex] atom in total; [tex]l = 1[/tex] for each of these electrons because of the
Therefore, a ground-state [tex]\rm _{21}Sc[/tex] atom would include [tex]12[/tex] electrons with [tex]l = 1[/tex].
A sample of ammonium phosphate, (NH4)3PO4, contains 0.104 mol of nitrogen atoms. The number of moles of oxygen atoms in the sample is
Answer:
There are 0.1387 moles of oxygen atoms.
Explanation:
First we calculate how many moles of ammonium phosphate there are:
There are 3 nitrogen moles per (NH₄)₃PO₄ mole.There are 0.104 nitrogen molesThus there are (0.104 mol N * [tex]\frac{1mol(NH_4)_3PO_4}{3molN}[/tex]) 0.0347 moles of (NH₄)₃PO₄.Finally we calculate how many moles of oxygen atoms are there in 0.312 moles of (NH₄)₃PO₄:
There are 4 oxygen moles per (NH₄)₃PO₄ mole.There are 0.0347 moles of (NH₄)₃PO₄.Thus there are (0.0347 mol (NH₄)₃PO₄ * [tex]\frac{4molO}{1mol(NH_4)_3PO_4}[/tex] ) 0.1387 moles of O.
The number of moles of oxygen atoms in the sample is 0.1388 mole
We'll begin by calculating the number of mole of (NH₄)₃PO₄ that contains 0.104 mole of N. This can be obtained as follow:
3 moles of N is present in 1 mole of (NH₄)₃PO₄.
Therefore,
0.104 mole of N will be present in = 0.104 / 3 = 0.0347 mole of (NH₄)₃PO₄.
Finally, we shall determine the number of oxygen atoms in the sample1 mole of (NH₄)₃PO₄ contains 4 mole of O.
Therefore,
0.0347 mole of (NH₄)₃PO₄ will contain = 0.0347 × 4 = 0.1388 mole of O
Thus, the number of moles of oxygen atoms in the sample is 0.1388 mole.
Learn more: https://brainly.com/question/11907810
Help needed urgently
the word missing or partially seen is oxygen I forgot to put more pointa
Explanation:
2.04 % hydrogen
32.65% sulphur
65.31% is oxygen
atomic ratio
hydrogen =2.04÷1=2.04
sulphur =32.65÷32=1.02
oxygen =65.31÷16=4.08
simplest ratio
hydrogen = 2.04÷1.02=2
sulphur =1.02÷1.02=1
oxygen =4.08÷1.02=4
empirical formula is H2SO4
What is weathering?
A.
the process by which sediment is compacted into rock
B.
the process by which rocks are broken down into sediment
C.
the process by which sediment is transported from one place to another
D.
the process by which sediment is deposited and built up into landforms
Answer:
B.
the process by which rocks are broken down into sediment
A Child with severe poison ivy weighs 25kg. The medicine needed is Benadryl po and for treatment 5mg of Benadryl is required for every 1 kg of the child. The Benadryl is available as a 12.5mg/5mL solution. If one dose of this medicine is equal to 12.5 mL ( 1dose = 12.5mL) how many doses are needed?
Number of doses needed : 4 doses
Further explanationGiven
weight of the child : 25 kg
Treatment of Benadryl : 5 mg/kg weight
The concentration of Benadryl : 12.5 mg/5 ml
1 dose = 12.5 ml
Required
Number of doses needed
Solution
Amount of Benadryl for 25 kg weight :
[tex]\tt 25~kg\times 5~\dfrac{mg}{kg}=125~mg[/tex]
Amount of Benadryl solution :
[tex]\tt \dfrac{125~mg}{12.5~mg/5~ml}=125~mg\times \dfrac{5~ml}{12.5~mg}=50~ml[/tex]
Amount of doses :
[tex]\tt \dfrac{50~ml}{12.5~ml}=4~doses[/tex]
What is Density in chemistry
Answer:
The density of something is the connection between the mass of the substance and how much space it takes up
Question 19 of 25 The atomic number of the element radium is 88. How many neutrons does radium-226 have?
A. 98
B. 138
C. 88
D. 116
E. 226
please i need this
Answer:
B. 138
Explanation:
Based on isotope notation:
[tex]^X_nA[/tex]
For the atom A, the mass number, X, is the sum of neutrons and protons and
n is the number of protons = Atomic number.
The number of protons depends of the nature of the atom. For example, Carbon has 12 protons, hydrogen 1 and Radium has 88 protons.
The radium-226 means the mass number is 226. Thus, number of neutrons are:
Mass number - Atomic number
226 - 88 = 138
Right answer is:
B. 138Answer:
Unit 4 Lesson 2:
Energy Release Quick Check
1. 138 neutrons
2. The conversion of an atom of one element into a different element through nuclear changes.
3. A nuclear equation is balanced according to mass number. A chemical equation is balanced according to the total mass before and after the change.
4. 82
5. Some of the matter is converted to energy.
Please give me Brainliest. You're Welcome
Look at the diagram of a fuel cell used to power a motorized vehicle. A fuel cell with 2 vertical objects labeled A and B connected by an electrical wire through a circle with a M in it; that circle is labeled A. There is an area between the two vertical objects, and substances flowing to, along, and away from the vertical objects and to the left and right. Which part of the fuel cell does A represent? anode cathode electrolyte motor
Answer: Its D. motor
Explanation:
TRUST ME ITS RIGHT
A fuel cell is an electrochemical device that generates electricity through reactions. A represents the electrolyte of the cell. Thus, option c is correct.
What is an electrolyte?
An electrolyte is a solution capable of conducting electricity through them because of its charged particle nature. The dissolved salts and ions are the carriers of electricity.
Anode and cathode are the two plate terminal that is charged and attracts the oppositely charged particles dissolved in the solution to conduct the electricity. The motor converts the energy onto electricity.
Therefore, option c. labeled part A is an electrolyte.
Learn more about electrolytes here:
https://brainly.com/question/16193219
#SPJ2
what is the dispersing medium in a colloid??
Explanation:
A colloid is a heterogeneous mixture whose particle size is intermediate between those of a solution and a suspension. The dispersed particles are spread evenly throughout the dispersion medium, which can be a solid, liquid, or gas.
Read the excerpt from Kennedy’s inaugural address. To those people in the huts and villages of half the globe struggling to break the bonds of mass misery, we pledge our best efforts to help them help themselves, for whatever period is required—not because the communists may be doing it, not because we seek their votes, but because it is right. If a free society cannot help the many who are poor, it cannot save the few who are rich. What is the main type of appeal that Kennedy uses in this excerpt? an ethical appeal to demand that the communists help around the globe an emotional appeal to emphasize the United States' commitment to justice a logical appeal to help people in poverty since there is no need to help the rich a logical appeal to explain why people around the globe cannot vote for a better life
Answer:
an emotional appeal to emphasize the United States' commitment to justice
Explanation:
The main type of appeal that Kennedy uses in this excerpt is an emotional appeal to emphasize the United States' commitment to justice. Therefore, option B is correct.
What is an appeal?In rhetoric, an appeal is a persuasive approach used to persuade an audience to believe or do something. Appeals can take many forms, but they generally fall into three categories: pathos, ethos, and logos.
Pathos appeals to the audience's emotions, ethos appeals to the credibility of the speaker or source, and logos appeals to the audience's sense of logic and reason.
Effective communication usually involves the use of multiple appeals to convince the audience to accept a particular perspective or take a particular action. Therefore, option B is correct.
Learn more about appeals, here:
https://brainly.com/question/8643122
#SPJ5
Give the mechanistic symbols (SN1, SN2) that are most consistent with each other the following statements:a) Methyl halides react with sodium ethoxide in ethanol only by this mechanism.b) Unhindered primary halides react with sodium ethoxide in ethanol mainly by this mechanis.c) The substitution product obtained by solvolysis of tert- butyl bromide in ethanol arises by this mechanism.d) Reactions proceeding by this mechanism are stereospecfic.e) Reactions proceeding by this mechanism involve carbocation intermediates.f) this mechanism is most likely to have been involved when the products are found to have a different carbon skeleton from the substrate.g) Alkyl iodides react faster than alkyl bromides in reactions that proceed by these mechanisms.
Answer:
very comfusing
Explanation:
Help me please!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Answer:
Wave 2
Explanation:
Higher frequency means more energy per second, And wave 2 has higher frequesncy
please mark brainliest I’m almost at expert level
Answer:
I believe it is wave 2
Explanation:
As you can see in the graph, wave two happens to be more frequent. There are well, more waves than the first graph. Please forgive me if I am wrong. I tried my best to explain
Do you think science will end the world or save the world or do neither?
Answer:
This is all up to you
Explanation: This question is up to you because you may think both or just one.
This infected cut has activated an ________ response
inflammatory
O pathogens
O skin
Answer:
Inflammatory
Explanation:
Calculate the molality of a 5.73 M ethanol (C2H5OH) solution whose density is 0.9327 g/mL.
Answer:
Molality = 8.57 m
Explanation:
Given data:
Molarity of solution = 5.73 M
density = 0.9327 g/mL
Molality of solution = ?
Solution:
Molality = moles of solute / kg of solvent.
Kg of solvent:
Mass of 1 L solution = density× volume
Mass of 1 L solution = 0.9327 g/mL × 1000 mL
Mass of 1 L solution = 932.7 g
Mass of solute:
Mass of 1 L = number of moles × molar mass
Mass = 5.73 mol × 46.068 g/mol
Mass = 263.97 g
Mass of solvent:
Mass of solvent = mass of solution - mass of solute
Mass of solvent = 932.7 g - 263.97 g
Mass of solvent = 668.73 g
In Kg = 668.73 /1000 = 0.6687 Kg
Molality:
Molality = number of moles of solute / mass of solvent in Kg
Molality = 5.73 mol / 0.6687 Kg
Molality = 8.57 m
Considering the definition of molality , you obtain that the molality of a 5.73 M ethanol (C₂H₅OH) solution whose density is 0.9327 g/mL is 8.57 [tex]\frac{moles}{kg}[/tex].
Molality is the ratio of the number of moles of any dissolved solute to kilograms of solvent.
The Molality of a solution is determined by the expression:
[tex]Molality=\frac{number of moles of solute}{kilogramof solvent}[/tex]
You have a 5.73 M ethanol (C₂H₅OH) solution whose density is 0.9327 g/mL.
Molarity is the number of moles of solute that are dissolved in a certain volume.
In this case, taking into account that the volume considered is 1 L, the number of moles of solute is 5.73 moles.
On the other side, density is the ratio of the weight (mass) of a substance to the volume it occupies. So, being 1 mL= 0.001 L, 0.9327 g/mL means that you have 0.9327 grams per 1 mL or 932.7 g per 1 L.
So, being the mass of solution calculated as number of moles multiplied by the molar mass, and being the mass of the solution 932.7 grams in 1 L, the mass of water is:
Mass of solvent = mass of solution - mass of solute
Mass of solvent = mass of solution - number of moles× molar mass
Mass of solvent = 932.7 g - 5.73 mol× 46.068 g/mol
Mass of solvent = 932.7 g - 263.97 g
Mass of solvent = 668.73 g= 0.66873 kg
Then, the molality can be calculated as:
[tex]Molality=\frac{5.73 moles}{0.66873 kg}[/tex]
Solving:
molality= 8.57 [tex]\frac{moles}{kg}[/tex]
Finally, the molality of a 5.73 M ethanol (C₂H₅OH) solution whose density is 0.9327 g/mL is 8.57 [tex]\frac{moles}{kg}[/tex].
Learn more about:
density: brainly.com/question/952755?referrer=searchResults brainly.com/question/1462554?referrer=searchResults molalitybrainly.com/question/20366625?referrer=searchResults brainly.com/question/4580605?referrer=searchResults molarity with this example: brainly.com/question/15406534?referrer=searchResults10.
What type of pest control uses pesticides, insecticides, and herbicides?
Cultural
Mechanical
Chemical
Biological
A
D
Answer:
C.
Explanation:
If pollution near factories was reduced, what
would happen to the color of the moths
Answer:
It would most likely just change their color
Explanation: The frequency of dark-coloured moths increased at that time, an example of industrial melanism. Later, when pollution was reduced, the light-coloured form again predominated. ... The dark-coloured or melanic form of the peppered moth
If pollution near factories was reduced, then this situation increased the frequency of white moths.
What is industrial melanism?Industrial melanism is an evolutionary feature associated with the increase of dark moths in industrial polluted areas.
Industrial melanism is an adaptation to survive these industrial conditions.In conclusion, if pollution near factories was reduced, then this situation increased the frequency of white moths.
Learn more about industrial melanism here:
https://brainly.com/question/15283847
#SPJ2
Want some points??
Answer:
yea i do
Explanation:
LETSSS GOOOOOO
Click the links to open the resources below. These resources will help you complete the assignment. Once you have created your file(s) and are ready to upload your assignment, click the Add Files button below and select each file from your desktop or network folder. Upload each file separately.
Your work will not be submitted to your teacher until you click Submit.
Documents
Constructing a Device to Regulate the Release of Energy - Student Guide
Constructing a Device to Regulate the Release of Energy - Rubric
File Upload
Accepted file types: .ppt, .pptx, .xls, .xlsx, .doc, .docx, .zip, .pdf, .accdb, .msg
Answer:
I am not able to click anything above!
Which of the following is a characteristic of all chemical changes?A. A different state of matter is produced. B. Some mass is converted to energy. C.Some form of light is given off. D. A new material is formed
how it is this???????
Answer:
1) Helium (2 electrons)
2) Neon (10 electrons)
3) Argon (18 electrons)
4) Krypton (36 electrons)
Identify the formula for an alkene.
A. CnH2n
B. CnH2n 2
C. CnH2n 4
C. CnH2n-2
D. CnH2n-4
Answer:
CnH2n-2
im pretty sure thats the answer
Predict the molecular geometry about N in the molecule CH3NHCH3
A. linear
B. trigonal pyramidal
C. bent
D. trigonal planar
The molecular geometry about N in the molecule CH3NHCH3 is trigonal pyramidal. Therefore, option B is correct.
What is molecular geometry ?The three-dimensional arrangement of the atoms that make up a molecule is known as molecular geometry. It includes the molecule's general shape as well as bond lengths and bond angles.
A molecule is trigonal planar if it has three bonds and no lone pairs. A molecule is bent or angular if it has three bonds and one lone pair. Tetrahedral molecules have four bonds and no lone pairs. A molecule is trigonal pyramid if it has four bonds and one lone pair.
Three of the five nitrogen electrons in NH3 are involved in bonding with three hydrogen atoms, while the unbounded two electrons form the single unshared pair of electrons. Ammonia has a trigonal pyramidal shape due to this lone pair.
Thus, option B is correct.
To learn more about molecular geometry, follow the link;
https://brainly.com/question/7558603
#SPJ5
When a living organism is successful in meeting all its needs ,this is called
A.active transport
B.endocytosis
C.homeostasis
D.exocytosis
Answer:
homeostasis
Explanation:
source Wiki
In biology, homeostasis (or “health”) is the state of steady internal, physical, and chemical conditions maintained by living systems. This is the condition of optimal functioning for the organism and includes many variables, such as body temperature and fluid balance, being kept within certain pre-set limits (homeostatic range). Other variables include the pH of extracellular fluid, the concentrations of sodium, potassium and calcium ions, as well as that of the blood sugar level, and these need to be regulated despite changes in the environment, diet, or level of activity. Each of these variables is controlled by one or more regulators or homeostatic mechanisms, which together maintain life.
A solution is made by dissolving
14.57 g of sodium bromide (NaBr) in
415 g of water.
What is the molality of the solution?
[?] m NaBr
Molar mass of NaBr: 102.89 g/mol
Answer:
0.342 m
Explanation:
From the question given above, the following data were obtained:
Mass of NaBr = 14.57 g
Mass of water = 415 g
Molar mass of NaBr = 102.89 g/mol
Molality of NaBr =?
Next, we shall determine the number of mole in 14.57 g of NaBr. This can be obtained as follow:
Mass of NaBr = 14.57 g
Molar mass of NaBr = 102.89 g/mol
Mole of NaBr =?
Mole = mass / molar mass
Mole of NaBr = 14.57 / 102.89
Mole of NaBr = 0.142 mole
Next, we shall convert 415 g of water to kg. This can be obtained as follow:
1000 g = 1 Kg
Therefore,
415 g = 415 g × 1 Kg / 1000 g
415 g = 0.415 Kg
Thus, 415 g is equivalent to 0.415 Kg.
Finally, we shall determine Molality of the solution as follow:
Mole of NaBr = 0.142 mole
Mass of water = 0.415 Kg
Molality of NaBr =?
Molality = mole / mass of water in Kg
Molality of NaBr = 0.142 / 0.415
Molality of NaBr = 0.342 m
Therefore, the molality of NaBr solution is 0.342 m.
Answer:
0.341
Explanation:
as stated underneathe the 'tutor verified' answer. lol
Which of the following is an example of a velocity?
30 miles per hour
30 miles per hour North
30 miles
30 hours
Answer:
30 miles per hour North
Explanation:
Velocity can be defined as the rate of change in displacement (distance) with time. Velocity is a vector quantity and as such it has both magnitude and direction.
Mathematically, velocity is given by the equation;
[tex]Velocity = \frac{distance}{time}[/tex]
[tex]V = \frac{d}{t}[/tex]
Hence, 30 miles per hour North is an example of a velocity because it is a vector quantity that has both magnitude and direction.
a huge tank contains 80,000 liters of oxygen, at a pressure of 760mmHg. If the oxygen is to be replaced into cylinder of 20 liters capacity at a pressure of 3040mmHg, how many cylinders will be needed?
how many molecules are contained in 7.85 moles of oxygen molecules?
Answer:
125.59528999999982
Explanation:
In the complex ion [Cr(C204)2(H20)2]-, what is the oxidation number of Cr?
O A. 3+
O B. 1+
O C.2+
OD. 2-
O E. 1-
Answer:
A. 3+
Explanation:
In the complex, the global charge is -1.
There are 2 molecules of H₂O but water is a neutral ligand that doesn't contribute any charge to the complex
In contrast, the C₂O₄ ligand has a charge of -2. As there are 2 C₂O₄, the charge is -4.
The -4 + The charge of Cr is equal to global charge of the complex ion = -1.
Thus, Cr has a charge of +3 and right answer is:
A. 3+
A single bond contains ____ shared electrons.
A single bond contains two shared electrons.