HELP! How is the mass number of an atom calculated?
A - total number of electrons
B - total number of protons
C - protons plus neutrons
D - electrons plus neutrons
10. At 573K, NO2(g) decomposes forming NO and O2. The decomposition reaction is second order in NO2 with a rate constant of 1.1 M-1s-1. If the initial concentration of NO2 is 0.056 M, how long will it take for 75% of the NO2 to decompose
Answer:
48.67 seconds
Explanation:
From;
1/[A] = kt + 1/[A]o
[A] = concentration at time t
t= time taken
k= rate constant
[A]o = initial concentration
Since [A] =[A]o - 0.75[A]o
[A] = 0.056 M - 0.042 M
[A] = 0.014 M
1/0.014 = (1.1t) + 1/0.056
71.4 - 17.86 = 1.1t
53.54 = 1.1t
t= 53.54/1.1
t= 48.67 seconds
Hence,it takes 48.67 seconds to decompose.
PLEASE HELP ASAP!!!
Answer:
I don't know What can I do.
A piece of metal has a volume of 30.0cm3 and a mass of 252g. What is its density? what metal do you think this is?
Answer:
Explanation:
get density = D = m / V = 0.252 / 0.00003 = 8400 metal will be Cu => bronzeDetermine the number of moles of aluminum in 2.154 x 10-1 kg of Al. Group of answer choices 5816 mol 7.984 mol 6.02 X 1023 mol 4.801 mol 8.783
Answer:
Avogadro's number is 1 mol = 6.02 * 10^23 elements
It means that 1 mol of atoms is 6.02 * 10^23 atoms
1 mol of atoms = 6.02 * 10^23 atoms
From there, if you divide both sides by 1 mol of atoms, you get
1 = 6.02 * 10^23 atoms / 1 mol of atoms.
That means, that to pass from a number of moles of atoms to number of atoms you have to multipby by the conversion factor
6.02*10^23 atoms Al/ 1 mol Al
That is the second option of the list.
Explanation:
Hello, I am a bit stuck on this. Could someone help?
What does the third quantum number (m) describe?
A. Which energy level the electron is in
B. What type of orbital the electron is in
C. What direction the electron is spinning
D. The specific orbital within a sublevel
The third quantum number (m) describes the specific orbital within a sublevel. The correct answer is option D.
Quantum numbers are a set of four numbers that describe the properties of an electron in an atom. They specify the energy, position, and orientation of an electron in an atom.
The third quantum number (m) is also called the magnetic quantum number. It describes the orientation of the orbital in space. Each orbital within a sublevel has a different orientation in space, and the magnetic quantum number tells us which orbital we are talking about.
The value of m can range from -l to +l, where l is the second quantum number (the angular momentum quantum number). The value of l determines the number of orbitals in a sublevel, and the value of m determines the specific orbital within that sublevel.
In conclusion, the third quantum number (m) describes the specific orbital within a sublevel. It tells us how the orbital is oriented in space, and it can have values ranging from[tex]\rm -l \ to +l[/tex], where l is the second quantum number.
Option D is the correct answer.
Learn more about quantum number here:
https://brainly.com/question/32116992
#SPJ4
Forcus on the yellow highlighted texts, your help is appreciated.
[tex]{ \sf{ \red{no \: pranks}}}[/tex]
Answer:
Transition temperature is the temperature at which a substance changes from one state to another.
Allotropy is the existence of an element in many forms.
When hydrogen gas reacts with oxygen gas, water vapour is formed according to the
reaction 2H2 + O2 2H2O. If 3.00 mol of hydrogen gas react with 3.00 mol
of oxygen gas, which reactant will be the reactant in excess?
Explanation:
here's the answer to the question
Hypercalcemia sign and symptoms severe symptoms
Answer:
Hypercalcemia can cause stomach upset, nausea, vomiting and constipation. Bones and muscles. In most cases, the excess calcium in your blood was leached from your bones, which weakens them. This can cause bone pain and muscle weakness.
Some symptoms are:
Fatigue, bone pain, headaches.
Nausea, vomiting, constipation, decrease in appetite.
Forgetfulness.
Lethargy, depression, memory loss or irritability.
Muscle aches, weakness, cramping and/or twitches.
A fusion reaction releases energy because the binding energy of the resulting nucleus:______.
a. is released in the process.
b. is equal to the binding energy of the original nuclei.
c. is absorbed in the process.
d. is less than the binding energy of the original nuclei.
e. is greater than the binding energy of the original nuclei.
Answer:
a. is released in the process
Explanation:
In fusion reaction the nucleus is unstable so it releases its binding energy resulting in decreasing its mass so it becomes more stable.
Write balanced equations for the reaction of each of the following carboxylic acids with NaOH. Part A formic acid Express your answer as a chemical equation. A chemical reaction does not occur for this question. Request Answer Part B 3-chloropropanoic acid Express your answer as a chemical equation. nothing A chemical reaction does not occur for this question.
Answer:
Part A
HCOOH(aq) + NaOH(aq) → HCOONa(aq) + H2O(l)
Part B
ClCH2CH2CO2H(aq) + NaOH(aq) ------> ClCH2CH2CO2Na(aq) + H2O(l)
Explanation:
The reaction between an alkanoic acid and a base is a neutralization reaction. The reaction occurs as follows;
RCOOH + NaOH ----> RCOONa + H2O
We have to note the fact that the net ionic reaction still remains;
H^+(aq) + OH^-(aq) ---> H2O(l)
In both cases, the reaction can occur and they actually do occur as written.
A central atom has two lone pairs on opposite sides and four single bonds. What is the molecule geometry of the result?
A. octahedral
B. tetrahedral
C. square planar
D. linear
The correct answer is C. square planar
According to the Valence Shell Electron Pair Repulsion Theory(VSEPR), The shape of a molecule depends on the number of electron pairs in the molecule.
VSEPR theory was first coined by Gillespie and Nyhlom in 1957 as an improvement over the Sidgwick - Powell theory.
According to this theory, the shape of a molecule is determined by the number of electron pairs that surround the valence shell of the central atom in the molecule. The electron pairs are positioned as far apart in space as possible to minimize repulsion of electron pairs.
However, the presence of lone pairs distorts the shape anticipated for the molecule on the basis of VSEPR.
For a molecule having six electron pairs, an octahedral geometry is expected(electron domain geometry). However, the presence of two lone pairs which are positioned at opposite side of the four single bonds leads to an observed square planar molecular geometry.
https://brainly.com/question/13591921
Answer:
square planar
Explanation:
The Lewis dot model of a molecule is shown.
Based on the model, which of the following is true?
Each carbon has three lone pairs of electrons on it.
The octet of carbon atom remains incomplete in the molecule.
The two carbon atoms share a total of six electrons with each other.
The difference between the electronegativity of carbon and hydrogen is greater than 1.7.
Answer:
The two carbon atoms share a total of six electrons with each other.
Explanation:
Looking at the structure of the molecule H-C≡C-H as shown in the question, we will notice that there exists a triple bond between the two carbon atoms.
Each bond between the two carbon atoms represents two electrons shared. Since there are three bonds between the two carbon atoms, then a total of six electrons were shared between the two carbon atoms hence the answer chosen above.
313.9 liters of a gas has a pressure of 390.89 kPa at 76.6°C. If the pressure increases to 718.3 kPa and the temperature to 154.2°C, what would be the new volume of the gas?
A.) 210
B.) 353
C.) 470
D.) 209.92
Explanation:
P1V1/T1 = P2V2/T2
=((390.89×313.9)/76.6)×((718.3×V2)/154.2)
= (122700.371/76.7) × ((718.3×V2)/154.2)
make V2 the subject of the formula...
V2 =(122700.371×154.2)/(76.6×718.3)
V2 =18920397.21/55021.78
V2 = 343.87
a. You have a stock solution of 14.8 M NH3. How many milliliters of this solution should you dilute to make 1000.0 mL of 0.250 M NH3?
b. If you take a 10.0 mL portion of the stock solution and dilute it to a total volume of 0.500 L, what will be the concentration of the final solution?
Answer:A) V = 16.892 ml
Explanation:
M1 * V1 = M2 * V2
14.8 M * V1 =0.250 M * 1000 ml
V1 = 16.892 ml
a. The volume of 16.89 milliliters of the stock solution of 14.8 M should be diluted to make 1000.0 mL of 0.250 M.
b. The concentration of the final solution is 0.296 M.
What is the dilution law?The concentration or the volume of the concentrated or dilute solution can be calculated by using the equation:
M₁V₁ = M₂V₂
where M₁ and V₁ are the concentration and volume of the concentrated solution respectively and M₂ and V₂ are the concentration and volume of the dilute solution.
A stock solution is a solution that has a high concentration and that will be diluted to a low concentration by the addition of water in it.
Given, a stock solution of concentration, M₁ = 14.8 M
The concentration of the diluted solution, M₂ = 0.250 M
The volume of diluted solution, V₂ = 1000ml
Substitute the value of the molarity and volume in equation (1):
(14.8)× (V₁) = (1000) × (0.250)
V₁ = 16.89 ml
Similarly, for part (b): M₁ = 14.8 M, V₁ = 10 ml and V₂ = 0.5L = 500 ml
(14.8)× (10) = (500) × (M₂)
M₂ = 0.296 M
Learn more about dilution law, here:
https://brainly.com/question/15718488
#SPJ5
Consider the reaction: A(aq) + 2B (aq) === C (aq). Initially 1.00 mol A and 1.80 mol B
were placed in a 5.00-liter container. The mole of B at equilibrium was determined to
be 1.00 mol. Calculate K value.
0.060
5.1
25
17
Ugh
Answer:
17
Explanation:
Step 1: Calculate the needed concentrations
[A]i = 1.00 mol/5.00 L = 0.200 M
[B]i = 1.80 mol/5.00 L = 0.360 M
[B]e = 1.00 mol/5.00 L = 0.200 M
Step 2: Make an ICE chart
A(aq) + 2 B(aq) ⇄ C(aq)
I 0.200 0.360 0
C -x -2x +x
E 0.200-x 0.360-2x x
Then,
[B]e = 0.360-2x = 0.200
x = 0.0800
The concentrations at equilibrium are:
[A]e = 0.200-0.0800 = 0.120 M
[B]e = 0.200 M
[C]e = 0.0800 M
Step 3: Calculate the concentration equilibrium constant (K)
K = [C] / [A] × [B]²
K = 0.0800 / 0.120 × 0.200² = 16.6 ≈ 17
Gu
Magnesium metal is reacted with hydrochloric acid to produce
hydrogen gas. A sample of hydrogen gas is collected over water
in a eudiometer at 28.0°C. The atmospheric pressure is 636
mmHg. Determine the pressure (in atm) of the hydrogen gas
produced
Pressure =
atm
The pressure of hydrogen gas is 607.7 mmHg
According of Dalton's law of Partial pressure, the total pressure of a mixture of gases is the sum of the partial pressures of the individual gases in the mixture.
We can now write;
The for hydrogen collected over water, we have a mixture of hydrogen gas and water vapour.
Total pressure = pressure of hydrogen gas + vapour pressure of water
Pressure of hydrogen gas = Total pressure - vapour pressure of water
Pressure of hydrogen gas = 636 mmHg - 28.3 mmHg
Pressure of hydrogen gas = 607.7 mmHg
For more information see https://brainly.com/question/14119417
How did Kepler's discoveries contribute to astronomy?
O They supported the heliocentric model.
O They established the laws of planetary motion.
O They explained how the Sun rises and sets.
O They made astronomy accessible to people who spoke Italian.
They made astronomy accessible to people who spoke italian
Answer:
"They established the laws of planetary motion"
Explanation:
Mr. Kepler was the astronomer who came up with the "Laws of Planetary Motion."
Complete the following nuclear equations. I recommend filling in the atomic number below each symbol. Instead of using superscripts in our answers, put each answer in the corresponding box. A). 54Fe 4He --> 2 1n _____
Answer:
gamma ray
Explanation:
cuales son las caracteristicas de el livermorio
Answer:
Livermorium is a radioactive, artificially produced element about which little is known. It is expected to be a solid and classified as a metal. It is a member of the chalcogen group. Livermorium has four isotopes with known half-lives, all of which decay through alpha decay
The surface of silver metal, Ag(s), became tarnished when it was exposed to oxygen, producing Ag2O. In Ag2O, the oxidation state of silver is 1. According to this information, silver metal was _____. Please choose the correct answer from the following choices, and then select the submit answer button. Answer choices reduced
Answer: The silver metal was OXIDIZED.
Explanation:
OXIDATION is defined as loss of electrons and increase in oxidation number of an atom.
Oxidation number is the charge on an ion in an ionic compound or the charge that an atom in a covalent compound would have it it were ionic. There are basic rules governing oxidation number, they include:
--> the oxidation number of elements in their free states is ZERO. Example O2, Cl2,Na, Al, Ag.
-->The oxidation number for an ion is the same as the size and sign of the charge on the ion. For example the oxidation number of Zn2+ is +2.
--> the sum of all the oxidation numbers of the elements in a compound is zero.
--> oxidation numbers are always written with either a positive or a negative sign.
On the other hand, reduction is the opposite of oxidation. As oxidation is taking place, reduction is also taking place. Reduction involves:
--> Gain of electron and
--> decrease in oxidation number
From the question, the silver metal had ZERO as it's oxidation number because it's in free state. After being exposed to oxygen to form silver oxide, the oxidation number became +1.
Since there is an increase in the oxidation number, the silver metal was OXIDIZED
A chemist is preparing to carry out a reaction that requires 5.75 moles of hydrogen gas. The chemist pumps the hydrogen into a 10.5 L rigid steel container at 20.0 °C. To what pressure, in kPa, must the hydrogen be compressed? (Show all work for full credit and circle your final answer) *
Answer:
The hydrogen must be compressed to 1333.13302 kPa.
Explanation:
An ideal gas is characterized by three state variables: absolute pressure (P), volume (V), and absolute temperature (T). The relationship between them constitutes the ideal gas law, an equation that relates the three variables if the amount of substance, number of moles n, remains constant and where R is the molar constant of the gases:
P * V = n * R * T
In this case:
P= ?V= 10.5 Ln= 5.75 molesR= 0.082 [tex]\frac{atm*L}{mol*K}[/tex]T= 20 C= 293 K (being 0 C= 273 K)Replacing:
P* 10.5 L= 5.75 moles* 0.082 [tex]\frac{atm*L}{mol*K}[/tex] * 293 K
Solving:
[tex]P=\frac{5.75 moles* 0.082 \frac{atm*L}{mol*K} * 293 K}{10.5 L}[/tex]
P= 13.157 atm
If 1 atm is equal to 101.325 kPa, then 13.157 atm is equal to 1333.13302 kPa.
The hydrogen must be compressed to 1333.13302 kPa.
what is the bond energy required to break one mole of carbon-carbon bonds
Answer:
100 kcal of bond energy
Two methods by which we can conserve water and water the plants.
Answer:
Two methods which help us to conserve water are:
Sprinkler irrigation system: this irrigation has an arrangement of vertical pipes with rotating nozzles on the top. It is more useful in the uneven and sandy land where sufficient water is not available.
Drip irrigation system: this irrigation system has an arrangement of pipes or tubes with very small holes in them to water plants drop by drop just at the base of the root. It is very efficient as water is not wasted at all.
When a marble is dropped into a beamer of water
Answer:
The water will rise.Explanation:
hope this helps you
-Sweety<3The mass of the marble is greater than that of the water. The marble weighs more than an equivalent volume of the water. The force from dropping the marble breaks the surface tension of the water. The marble has greater mass and volume than the water.
J00
Sugar
(C2H2011)
260
KNO
220
180
Solubility (g solute per 100 g H,0)
140
NaNO,
NaBr
100
KBr
60
КСІ
Naci
20
0
0
20
Ce (50)
40 60
Temperature (°C)
80
100
Which compound would make a saturated solution if 98 grams were
dissolved in 100 grams of solution at 80 degrees Celsius?
O KBr
O Sugar
OKCI
O NaCl
alish
A person uses 400.8 kcal of energy to run a race. Convert the energy used for the race to the following energy units:
(provide an answer in 4 significant figures)
Calories
calories
Food Calories
Joules
Kilojoules
Hint: 1kcal=4.184kJ
Calories, we know that fat burn is calories.
In the graphic, 195 represents the _______.
195 Pt
78
A. Atomic Mass
B. Atomic Number
C. Neutron Number
Answer:
ITS ANSWER IS
OPTION B. ATOMIC NUMBER
HI HAVE A NICE DAY
How many milliliters of 0.204 Mol KMnO4 are needed to react with 3.24 g of iron(II) sulfate, FeSO4? The reation is as folows. 10FeSO4(aq) + 2 KMnO4(aq) = 5Fe2(SO4)3(aq) + 2MnSO4(aq) + K2SO4(aq) + 8H2O(l)
Answer:
Explanation:
nFeSo4=3.36/152
nkmno4=1/5nFeSO4
V=17.68 ml
