Answer:
Calculate the mass of BR -79? Bromine has 2 naturally occurring isotopes (Br-79 and Br-81) and has an atomic mass of 79.904 amu
Explanation:
if i get this wrong srry
List 5 foods that contain bacteria?
Why is it necessary to add concentrated HCl, then water, rather than a solution of HCl to the eudiometer tube
If we add water to a concentrated acid, then the solution may boil very violently, splashing concentrated acid. If add acid to water, the solution that forms is very dilute and a small amount of heat is released.
Why do we add acid to water?When a strong acid is poured into water, it flows down the flask and mixes much better, so no boiling takes place. The addition of water to acid forms an extremely concentrated solution of acid initially. A large amount of heat is released and the solution may boil very violently, splashing concentrated acid out of the beaker and all this because the reaction is exothermic in nature.
The reason this takes place is due to a large amount of energy liberated in the hydration reaction of concentrated ions. Therefore, we add acid to water dropwise for the dilution with constant stirring and not water to acid directly.
If we add water to acid, then an exothermic reaction occurs and the solution may boil very violently. To form the dilute solution of any strong acid, you should add acid to water and the small amount of heat released is not sufficient to vaporize and spatter it.
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C is the element symbol for which element?
a. Carbon
b. Cadmium
c. Celenium
d. Chlorine
Answer:
A) Carbon
Explanation:
the others are wrong its A
Answer:
A) carbon
Explanation:
carbon or simply c has an atomic number of 6 and it has an atomic mass of 12.01 amu. it belongs to group 4a
Which step is part of a scientific investigation?
O designing a solution
O implementing the solution
O evaluating the solution
O communicating the findings
A commonly held idea about influenza is that it is a disease that occurs primarily in cold weather. Doctors report incidences of illness, such as influenza, to the Centers for Disease Control (CDC). The graph below shows data for three flu seasons. Note that this graph shows data from October, week 40, of one year to July, week 28, of the following year.
Which evidence supports this idea?
The graph line for 2008-09 has the highest peaks for flu.
All three graph lines show different patterns throughout the year.
The graph line for 2008-09 has a peak in week 44.
All three graph lines peak over the same few weeks of winter.
Answer:
D.All three graph lines peak over the same few weeks of winter.
Explanation:
took the test
A scientist is considering formaldehyde (HCHO) for use in an experiment. She is studying the strength of triple bonds in molecules. Is
ormaldehyde a good choice for her to use? Why?
A. Yes, HCHO has three triple bonds.
B. Yes, HCHO has one triple bond.
C. No, HCHO has a double bond but no triple bonds.
D. No, HCHO has only single bonds.
every spring has an equilibrium position which statement describe a spring at it equilibruim position?
What color do you get if you mix red and blue light?
Red and Green?
Blue and green?
What relationship do you find between frequency and energy?
What relationship do you find between wavelength and current flow?
What relationship do you find between light intensity and current flow?
Answer:
Purple light.
Yellow light.
Explanation:
please help 10 points asap
Answer:
opposite
Explanation:
Answer:
opposite
Explanation:
cu9c9ucoucucpucfpufupfpucupvpjvpucu
what elements make up duralumin( an alloy)?
Answer:
In addition to aluminium, the main materials in duralumin are copper, manganese and magnesium.
Answer:
The original composition has been varied for particular applications; it may contain about 4 percent copper, 0.5–1 percent manganese, 0.5–1.5 percent magnesium, and, in some formulations, some silicon.
The atom is one of the basic units of matter. Which part of the atom mostly determines the size of the atom?
a.Electrons
b.Nucleus
c.Neutrons
d.Protons
Answer:
Atomic size is the distance from the nucleus to the valence shell where the valence electrons are located. The separation that occurs because electrons have the same charge. The number of protons in the nucleus. The core electrons in an atom interfere with the attraction of the nucleus for the outermost electrons.
Explanation:
That would be B I believe, but please correct me if I'm wrong.
TRUE OR FALSE? Alloys are used more than pure metals because they are generally softer and less likely to react with air or water. WILL GIVE BRAINLIEST
Answer:
False
Explanation:
They’re used cause they’re generally harder than pure metals
Alloys are used much more than pure metals because they are generally stronger and less likely to react with air or water...
So I would say false
A 7.28 g sample of chromium metal was heated to produce chromium oxide. The weight of the compound was 10.63 g. What is the percent chromium in this compound?
Answer:
68.48%
Explanation:
The percent mass of an element in a compound tells us about the amount of such element contributed to the total compound.
In this case, 7.28 g sample of chromium metal was heated to produce chromium oxide with weight of 10.63 g. The percent mass of chromium in chromium oxide can be calculated by using the formula:
%mass of Cr = mass of Cr/mass of Chromium oxide × 100%
%mass of Cr = 7.28/10.63 × 100
%mass of Cr = 0.6848 × 100
%mass of Cr = 68.48%
Which one of the following is NOT a proper unit for frequency? *
m·s–1
Hz
s–1
1/s
Answer:
m*s⁻¹.
Explanation:
Hello!
In this case, since the frequency measures how repetitive an event is per unit of time, for instance the laps a car drives every 5 minutes or something similar, we can infer it has units of event/time; in such a way, the unit m*s⁻¹ is not a proper unit of frequency because it is a proper unit of velocity which is the distance traveled per unit of time.
In such a way, Hz (hertz), s⁻¹ and 1/s are possible ways frequency can be represented.
Best regards!
A nuclear power plant is scheduled to undergo a retrofitting. What is the most likely outcome of the change?
The power plant will no longer generate radioactive wastes.
The power plant will recycle the water it uses to cool the reactor.
The power plant will be able to reprocess its used uranium fuel.
The power plant will switch from fission reactions to fusion reactions.
Answer:
It's B
Explanation:
I got it right on edjenuity
The most likely outcome of the retrofitting of a nuclear power plant is that it will be able to reprocess its used uranium fuel. Therefore, option C is correct.
What is nuclear power plant?A nuclear power plant is a facility that generates electricity by harnessing the heat produced by nuclear reactions. At the heart of a nuclear power plant is the reactor, where a controlled chain reaction of nuclear fission occurs.
Reprocessing is a process by which the used nuclear fuel is chemically treated to separate out and recover the unused uranium and plutonium, which can then be reused as fuel. This reduces the amount of radioactive waste produced by the plant and also extends the life of the uranium fuel.
The fission reactions to fusion reactions is not currently a viable option for power generation, and the idea that a retrofitting would eliminate radioactive wastes is unlikely, as nuclear power plants will always produce some amount of radioactive waste.
Thus, option C is correct.
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A Barometer reads 29.1 inches of mercury.Calculate this pressure in mmHg.
What is the answer?
This follows a simple conversion technique. Basically what the question is trying to say here is to convert 29.1 inHg to mmHg. 1 inHg is equal to 25.4 mmHg so 29.1 inHg would be equal to [tex]25.4 * 29.1[/tex] which when evaluated turns out to be: [tex]739.14[/tex]. :D
The pressure will be 739.14 mm Hg.
What is pressure?The SI unit measuring pressure would be the pascal, which measures the force of each unit area of the surface.
Calculation of pressure
It is known that 1inHg = 25.4 mm Hg.
Hence, the pressure = 25.4 × 29.1 = 739.14 mm Hg
Therefore, the pressure will be 739.14 mm Hg.
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Question 2 of 25
Rain exists in which phase?
O A Liquid
O B. Solid
C. Plasma
D. Gas
Answer:
liquid
Explanation:
correct answer hope it helps
formal charge of hcooh
Answer:
What is the question?
A baseball has serval properties. Write one property that a baseball has.
complete sentences.
A 12 gram piece of Cu at 475 oC is placed in contact with a 15 gram piece of Cr at 265 oC.
Assume the two pieces of metal are the system and that there is no heat exchange between system and surrounding.
What is the final temperature of the two pieces of metal expressed in degree C?
Answer:
349.22°C
Explanation:
Let the final temperature of the two pieces of metal be x.
Now, the warmer metal which is C u reduces from 475°C to x. Thus Δt for C u is; Δt1 = 475 - x.
The cooler metal Cr increases in temperature from 265°C to x. Thus, it's change in temperature is Δt for Cr is; Δt2 = x - 265.
Now from conservation of energy, the amount of energy leaving the C u metal is equal to the amount of energy entering the Cr metal.
Thus;
q_lost = q_gain
Where;
q_lost = m1•c1•Δt1
q_gained = m2•c2•Δt2
Now, c1 & c2 are the specific heat capacity of C u and Cr respectively.
From online tables, c1 = 0.385 J/g°C and c2 = 0.46 J/g°C
We are given;
m1 = 12g and m2 = 15g
Thus;
12 × 0.385 × (475 - x) = 15 × 0.46 × (x - 265)
2194.5 - 4.62x = 6.9x - 1828.5
6.9x + 4.62x = 2194.5 + 1828.5
11.52x = 4023
x = 4023/11.52
x = 349.22°C
Will give brainliest, Look at the graph above. Compare it to the periodic table. What do you notice about the location on the periodic table of the elements that represent the high points
Answer:
We can see that the atomic radius decreases across every row.
Explanation:
I will comment more below.
The elements that represent the highest points on the graph are all elements of group 1 and occur at the head of the period to which they belong.
The periodic table is an arrangement of elements in groups and periods. The elements in the same group have the same number of valence electrons while the elements in the same period have the same number of shells.
Looking at the graph, we can see that the high points in the graph all correspond to the group 1 elements; sodium, potassium, rubidium and cesium.The have the highest atomic radii in the period. Atomic radii increases down the group but decreases across the period. Remember that these elements are at the head of the period to which they belong hence they have the highest atomic radii.
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What is the specific rotation of a sample of carvone that is an equal mixture of the R and S enantiomers
Answer:
Zero
Explanation:
An an equal mixture of the R and S enantiomers of carvone is called a racemic mixture.
In a racemic mixture, the R enantiomer rotates plane polarized light in one direction while the S enantiomer rotates plane polarized light in another direction.
This cancels out the rotation due to each enantiomer since they are equal in magnitude but opposite in direction leading to a specific rotation of zero for the racemic mixture.
I need the answer multiple choice
Answer:
it's answer is
element of an atom ✌️
The three lines in this Lewis dot structure represent the.
A)
three valence electrons of dinitrous oxide.
B)
six electrons in the triple bond of diatomic nitrogen.
C)
three electrons joining two nitrogen atoms in a diatomic molecule.
D)
three double bonds between the valence electrons of diatomic nitrogen.
Answer:
B) . six electrons in the triple bond of diatomic nitrogen
Explanation:
The three line in this Lewis dot structure represents the six electrons in the triple bond of diatomic nitrogen.
Nitrogen is made up of 7 electrons with 5 valence ones.
A lewis structure is made up of the symbol of the element surrounded by dot to represent the valence electrons.
In this nitrogen molecule, both species share 6 electrons. This makes each nitrogen atom isoelectronic with neon.
An excess of oxygen reacts with 451.4 g of lead, forming 374.7 g of lead(II) oxide. Calculate the percent yield of the reaction.
Answer: The percent yield of the reaction is 77.0 %
Explanation:
[tex]2Pb+O_2\rightarrow 2PbO[/tex]
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]
[tex]\text{Number of moles of lead}=\frac{451.4g}{207.2g/mol}=2.18moles[/tex]
[tex]\text{Number of moles of lead oxide}=\frac{374.7g}{223.2g/mol}=1.68moles[/tex]
According to stoichiometry:
2 moles of [tex]Pb[/tex] produces = 2 moles of [tex]PbO_2[/tex]
2.18 moles of [tex]Pb[/tex] is produced by=[tex]\frac{2}{2}\times 2.18=2.18moles[/tex] of [tex]PbO_2[/tex]
Mass of [tex]PbO_2[/tex] =[tex]moles\times {\text {Molar mass}}=2.18\times 223.2g/mol=486.6[/tex]
percent yield =[tex]\frac{374.7g}{486.6g}\times 100=77.0\%[/tex]
PLEASE HELP ME!!!!!!!!!!!!!!!!!!!
WRITE A SHORT PASSAGE ON HOW FIBRES ARE SPUN
HELPPP WILL MARK AS BRAINLIEST
Answer: Spun yarn is made by twisting staple fibers together
To make a cohesive thread Or “single”. Twisting fibers, into yarn in the process called spinning can be dated back to the upper Paleolithic. Yarn spinning was one of the first processes to be industrialized.
Explanation:
Whenever the same two elements form more than one
compound, the different masses of one element that combine
with the same mass of the other element are in the ratio of
small whole numbers.
TRUE
FALSE
Answer:
The answer is true
Explanation: Because The law of multiple proportions states that when two elements react to form more than one compound, a fixed mass of one element will react with masses of the other element in a ratio of small, whole numbers.
HELP
What type of bond is formed between the carbon and either oxygen in CO2?
A) Single
B) Double
C) Triple
The atomic masses of 20Ne (90.48 percent), 21Ne (0.27 percent), and 22Ne (9.25 percent) are 19.9924356, 20.9938428, and 21.9913831 amu, respectively. Calculate the average atomic mass of neon. The percentages in parentheses denote the relative abundance
Answer:
20.180042 amu
Explanation:
From the question given above, the following data were obtained:
Isotope A (20Ne)
Mass of A = 19.9924356 amu
Abundance (A%) = 90.48%
Isotope B (21Ne):
Mass of B = 20.9938428 amu
Abundance (B%) = 0.27%
Isotope C (22Ne):
Mass of C = 21.9913831 amu
Abundance (C%) = 9.25%
Average atomic mass of Neon =.?
The average atomic mass of Neon can be obtained as follow:
Average atomic mass = [(mass of A × A%)/100] + [(mass of B × B%)/100] + [(mass of C × C%)/100]
= [(19.9924356 × 90.48)/100] + [(20.9938428 × 0.27) /100] + [(21.9913831 × 9.25) /100]
= 18.0891557 + 0.05668338 + 2.03420294
= 20.180042 amu
Therefore, the average atomic mass of Neon is 20.180042 amu
Why does the flask have to be closed during the hydrochloric acid and sodium carbonate reaction?
Answer:
The flask has to be closed during the hydrochloric acid and sodium carbonate reaction as the resultant gas got trapped inside the closed flask.
Explanation:
The hydrochloric acid and sodium carbonate reaction was exothermic that caused the pressure to decrease. The flask has to be closed during the hydrochloric acid and sodium carbonate reaction as the resultant gas got trapped inside the closed flask.
In exothermic reactions, energy is produced in the form of heat or light.