Answer:
to indicate the presence of acid or base in a body
please help me
Type the correct answer in the box. Spell all words correctly.
What does Dalton's atomic theory propose?
A ______ causes rearrangement of atoms.
How many protons,neutrons and electrons make a hydrogen atom
Explanation:
A hydrogen atom has an atomic number of 1.
So it's proton number will always be 1.
A neutral hydrogen atom does not have any charge.
So it has the same amount of electrons as protons, which turns out to be also 1.
A neutral hydrogen atom has an atomic mass of ≈1.00794amu≈1amu.
To find the amount of neutrons, we take the proton number and subtract it from the mass number.
1−1=0
So a neutral hydrogen atom has no neutrons.
In summary,
A hydrogen atom has
1 proton
1 electron
0 neutrons
another way of explaining:
The number of protons is the atomic number, and the number of protons plus neutrons is the atomic mass. For hydrogen, the atomic mass is 1 because there is one proton and no neutrons. For helium, it is 4: two protons and two neutrons
a substance that cannot be broken down into simpler substances
Elements are pure substances that cannot be broken down into simpler substances by ordinary chemical means.
Zn(s) + Cu2+ —> Zn2+(aq) + Cu(s)
In this reaction, copper __ electrons, therefore it is the __ agent.
A. loses, reducing
B. gains, oxidizing
C. loses, oxidizing
D. gains, reducing
Answer: do you guys know the answer
Explanation:
Answer:
gains,oxidizing
Explanation:
Zn(s) + Cu^2+---> Zn^2+(aq) + Cu(s)
I got the answer right on usatp.
column table in two words?
Answer:
a table is a grid of rows and columns that intersect to form cells
Explanation:
C3H4(g) + xO2(g) → 3C02(g) + 2H2O(g)
-
What is the value of the coefficient x in this
equation?
Answer:
4
Explanation:
atoms of O2 in the product side:
(3×2)+(2×1)=8
so to balance it:
x × 2 =8
x=4
Assume trilobites went extinct 248 million years ago.
If a trilobite is found in a rock layer, what do you
know about the age of that rock layer?
Answer:
the rock layer is at least 248 million years old
Explore
2. Which is true regarding water? A. Compound of element B. Element of gases C. Mixture of gases D. Substances of gases
D or A im not fully sure about my answer on that
4 Fe + 3 O2 ----> 2 Fe2O3
How many moles of iron(III) oxide, Fe2O3 , will be produced if 4 moles of iron, Fe, are consumed.
Answer:
320 gm
Explanation:
4 Fe + 3 O2 ----> 2 Fe2O3 How many moles of iron(III) oxide, Fe2O3 , will be produced if 4 moles of iron, Fe, are consumed
for every 4 moles of Fe, 2 moles of Fe2O3 are produced.
Fe2O3 has a molar mass of (56 X 2) + (16 X 3) = 112 + 48 =160
160 X 2 =320 gm
A. Parts of Solutions
1. The substance that exists in the greatest quantity in a solution is called
the
Answer:
a
Explanation:
the substance that exists
How many molecules of H2O are there in 200,000,000L of gas at STP?
Describe how to do an experiment to show that when you dissolve salt in water the salt is still there.
Answer:
When salt is dissolved in water, the particles of salt get into the spaces between particles of water and starts dissolving and disappear.
Explanation:
Two containers of gas have the same volume, temperature and pressure. One container has a sample of oxygen gas having a mass of 3.95g. The other container has a gas with a mass of 2.99g. Determine the molar mass of the gas in the second container.
Answer:
24.3
Explanation:
Two containers of gas have the same volume, temperature and pressure. One container has a sample of oxygen gas having a mass of 3.95g. The other container has a gas with a mass of 2.99g. Determine the molar mass of the gas in the second container.
O2 has a molar mass of 16 X 2 =32
the number of moles for O2 is the weight divided by the molar mass or, but since the two container have the same P,V, AND T they have the same number of moles since
PV =nRT
SO
the weight of the gas in the second container divided by its molar mass =
0.123
or
2.99/? = 0.123
so
? = 2.99/o.123 = 24.3
Carbon dioxide, when present in sufficient amounts, will bind with water to form ____________ , which is capable of dissociating into bicarbonate and hydrogen ions.
Answer:
Carbon dioxide, when present in sufficient amounts, will bind with water to form carbonic acid, which is capable of dissociating into bicarbonate and hydrogen ions.
Explanation:
With the help of carbonic anhydrase which further catalyzes the reaction to convert carbonic acid back into carbon dioxide and water. The carbon dioxide is then expelled from the lungs.
Based on the periodic table, what is the oxidation number of oxygen (Group VI, period 2) in compounds? a) 0 b) +2 C) -2 d) 1
The oxidation number of oxygen (Group VI, period 2) is -2.
The electrical charge of an atom describes its Oxidation number.\The number of electrons that must be gained or lost in an atom's valence electron shell to make it to be filled or half-filled gives us the oxidation number value.When the atom gains electrons,it acquires a negative oxidation number. When the atom loses electrons,it acquires a positive oxidation number
Oxygen has 8 electrons with {He] 2s² 2p⁴ configuration. With 6 electrons in its valence shell, it need to gain 2 electrons to achieve stability, When it gains 2 electrons, it acquires a negative oxidation number of -2.
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Look at the three kinds of houses shown in the simulation. Which house do you think will best resist damage from a tsunami? Which house will suffer the most damage from a tsunami? Do you think any of the houses will survive a large tsunami? Write down your predictions. https://app.edmentum.com/redirect//358692this link will help the people answer my question the link
Answer:
all the houses will be damaged
Explanation:
i voted for it
I need HELP A.S.P
B. A +ion (positive ion, one with extra positive charge)?
What mass of KBr (in grams) do you need to make 250. 0 mL of a 1. 50 MKBr solution?.
Answer:
KBr final solution:
V = 250mL --> 0.25L
Concentration/Molarity = 1.5 mol/L
To find the amount of moles of KBr here, just multiply the volume by the concentration (0.25 x 1.5 = 0.375 mol)
So the amount of moles for KBr is 0.375 mol. Now we know that the mass divided by the molar mass (the atomic mass values of K and Br in the periodic table added together) would give us the amount of moles aswell.
n = moles
m = mass
M = molar mass
n = m/M
so if we rearrange this equation to find mass, we would get:
m = n x M
Molar mass for KBr: (39.09) of K + (79.90) of Br = 118.99
m = 0.375 mol x 118.99
m = 44.62g
Therefore 44.62g of KBr is needed to make 250mL of a 1.5 M KBr solution.
What is the
name of the
compound
Na2Co3?
Answer:SODIUM CARBONATE
Explanation:
the electron pair geometry around the central iodine in I3- is
The electron pair geometry around the central iodine in I3- is trigonal bipyramidal.
The shapes of molecules is determined by the Valence Shell Electron Pair Repulsion theory (VSEPR). According to this theory, The shape of a molecule depends on the number of electron pairs that surround the valence shell of the central atom in the molecule.
In the structure I3-, the iodine is sp3d hybridized and has a bond angle of 180°. There are three iodine atoms. The central iodine atom is surrounded by two bond pairs and three lone pairs. The electron pair geometry around the central iodine in I3- is trigonal bipyramidal.
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when chlorine gains an electron to have 8 valence electrons and become stable, will it increase, decrease or stay the same in terms of the atomic radius
Answer:
It becomes an ion
Explanation:
The element it took from becomes a positive ion
And chlorine becomes a negative ion
how many electrons does Fe-55 have
Iron-55 (55Fe) is a radioactive isotope of iron with a nucleus containing 26 protons and 29 neutrons.
Answer:
54
Explanation:
yep
can someone send the working and answer for this question with formulas used and all
Answer:
its letter d ..................................
Count the following atoms
NEED ANSWER ASAP
How
many
moles is 2.55 X 1026 atoms of Neon?
Answer:
423.44 moles
Explanation:
:) help please I sent in a photo
Answer:
I think it's C I think that's the answer
Help here plz you guys
Recognize: What happens if a hypothesis is not supported.
Explain: Why do scientists practice scientific inquiry?
Describe: The behaviors scientists use in their work.
Answer:
If the initial hypothesis is not supported, you can go back to the drawing board and hypothesize a new answer to the question and a new way to test it. ... Either way, the process of experimentation often leads to whole new questions to explore.
Scientific inquiry uses evidence from observations and investigations to create logical explanations to answer questions related to science. Scientific inquiry is different from the scientific method. ... Scientific inquiry helps you think outside the box to understand the natural world.
Unlike social scientists, behavioral scientists collect empirical data and use experimental methods, including testing, controls and manipulated settings.
Explanation:
Which phrase best describes the vapor point of a substance?
the strength of the bonds between molecules of a substance that is in a gaseous state
the amount of heat energy required to change a substance from a liquid to a gas
the temperature at which additional heat energy causes the substance to change from a liquid to a gas
the average kinetic energy of the molecules of a substance in its gaseous state
The phrase which best describes the vapor point of a substance is Choice C; the temperature at which additional heat energy causes the substance to change from a liquid to a gas.
The vapour point of a substance by definition is the state of a substance at which upon addition of any amount of heat energy; he substance undergoes a phase change from liquid to solid.
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how does the molecular geometry change if you replace a bond with a lone pair?
Answer:
The overall molecular shape (the molecule geometry) changes because of the lone pairs repulsion, but the electron geometry does not change because whether an atom or a lone pair is added there's still two electrons being added.
Explanation:
hope that helps :D
Answer:
Un par solitario o par de electrones no compartidos es un par de electrones de valencia que no se encuentra formando un enlace, ni compartido con otros átomos. Cuando un átomo se agrupa con otros para formar una molécula, sus electrones más externos -también conocidos como electrones de capa de valencia- dejan de pertenecer únicamente al átomo del que provienen, pasando a pertenecer a la molécula formada. Los orbitales atómicos de valencia dejan de existir como tales y pasan a formar orbitales moleculares con características diferentes a las originales. Como los pares solitarios se encuentran en la capa más externa de los átomos, cuando estos átomos forman moléculas pasan a formar parte del conjunto de electrones de valencia de la molécula. De esto se deduce que los pares solitarios son, de hecho, un subconjunto de los electrones de valencia de la molécula a la que pertenecen.
Explanation:
espero que te sirva :)
Which of the following solutions represents a good buffer system? a solution that is 0. 10 mol L-1 HF and 0. 10 mol L-1 CH3COONa a solution that is 0. 10 mol L-1 HCl and 0. 10 mol L-1 NH4 a solution that is 0. 10 mol L-1 CH3COOH and 0. 10 mol L-1 CH3COOLi a solution that is 0. 10 mol L-1 NaOH and 0. 10 mol L-1 KOH a solution that is 0. 10 mol L-1 HCl and 0. 10 mol L-1 KCl.
Answer:
first
Explanation:
0. 10 mol L-1 HF and 0. 10 mol L-1 CH3COONa a solution that is 0 is a good buffer system. so, option A is correct.
What is buffer system ?When acids or bases are introduced, a buffer system is a solution that resists changing in pH. Acidic solutions have pH values under seven and significant hydrogen ion ( H+ ) concentrations. Basic solutions have pH values higher than seven and high quantities of hydroxide ions ( OH- ).
The carbonate, carbonic acid buffer, the phosphate buffer, and the buffering of plasma proteins make up the body's chemical buffer system.
Plasma proteins, phosphate, bicarbonate, and carbonic acid buffers are among the buffer systems active in blood plasma. By excreting hydrogen ions and producing bicarbonate, which helps keep blood plasma pH within a normal range, the kidneys contribute to the regulation of acid-base balance.
Thus, option A is correct.
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