Answer:
20
Explanation:
Hi there!
We need to find the atomic number of an atom that has 20 protons and 20 neutrons
the atomic number of an atom is equivalent to the amount of protons an atom has, as the number of protons determines what element an atom is.
Since the atom has 20 protons, the atomic number of the said atom is 20
Hope this helps!
What is the molarity of the solution formed by dissolving 80. G of NAOH(s) into water to give a total volume of 4.00 l
Answer:
0.5 M
Explanation:
From the question given above, the following data were obtained:
Mass of NaOH = 80 g
Volume of solution = 4 L
Molarity =?
Next, we shall determine the number of mole in 80 g of NaOH. This can be obtained as follow:
Mass of NaOH = 80 g
Molar mass of NaOH = 23 + 16 + 1
= 40 g/mol
Mole of NaOH =?
Mole = mass / molar mass
Mole of NaOH = 80 / 40
Mole of NaOH = 2 moles
Finally, we shall determine the molarity of the solution. This can be obtained as follow:
Mole of NaOH = 2 moles
Volume of solution = 4 L
Molarity =?
Molarity = mole / Volume
Molarity = 2/4
Molarity = 0.5 M
Therefore, the molarity of the solution is 0.5 M.
A new element R shows chemical properties similar to the element sodium. What is the correct formula of a compound formed with R and sulfur?
R₂S
RS₂
RS
R₂S₂
Answer:
R2S this is because sodium has one 1 valence and sulfur has valence of 2 so when they combine theyinterchange their valence
 Help ASAP only right answers only no spam don’t answer if you don’t know
i know the answer is a theory
What is the cause of acid precipitation?
1) ozone
2) nitrogenous oxides
3) ammonia
4) chlorofluorocarbons (CFCs)
Answer:
nitrogenous oxides
Explanation:
Acid rain is caused by a chemical reaction that begins when compounds like sulfur dioxide and nitrogen oxides are released into the air. ... In addition, the exhaust from cars, trucks, and buses releases nitrogen oxides and sulfur dioxide into the air. These pollutants cause acid rain.
The correct answer in you question is 2) nitrogenous oxide
I hope it helps ●~●
#CarryOnLearningWhich of the following make up an atom of gold? Select all that apply.
a
photons
b
electrons
c
neutrinos
d
protons
e
neutrons
Answer:
b, d, e
Explanation:
An atom is made up of electrons, protons and neutrons. Gold is an atom thus has the above particles.
Which phrase best describes a Hawaiian eruption?
A. Slow-moving lava flows and explosions of pumice
B. Ash shooting high into the atmosphere
C. Fast-moving lava flows and explosions of cinder
D. Lava fountains and fissure eruptions
Answer:
C.faste-moving lava flows and explosion of cinder
which of the following pairs are ionic compounds ( Al,Cl),(Na,O),(Al,F)
Answer:
This answer I think it is Al,F
A chemical bond formed when two atoms share two pairs of electrons is a ________ bond; it is best described as ________.
Answer:
A chemical bond formed when two atoms share two pairs of electrons is a double bond; it is best described as a covalent bond.
Explanation:
A chemical bond in which two pairs of electrons are shared has to be defined as covalent since ionic bonds don't involve electron sharing. They consist only of electrostatic attraction between ions.
How many ATOMS of boron are present in 3.61 grams of boron trifluoride ?
Hi there!
[tex]\large\boxed{3.203 * 10^{22} atoms}[/tex]
We can use the following conversions to solve:
Total mass --> amount of mols --> amount of atoms (Avogadro's number)
Begin by calculating the amount of boron trifluoride in 3.61 grams:
3.61 g * (1 mol BF₃ / 67.8 g) ≈ 0.0532 mol BF₃
Use avogadro's number to convert:
0.0532 mol * 6.02× 10²³atoms / 1 mol = 3.203 × 10²² atoms
How could the experiment be changed to allow for a result to be shown for the insoluble food
colouring?
Answer:
no lo se yo hablo en español no en ingles
True or false, In a neutral atom of an element, the number of protons always equals the number of electrons.
Answer:
true
Explanation:
As an atom with no charge have same number of proton and electrons
The enthalpy of a reaction is -394 kJ/mol. How would you describe the
reaction?
A. Spontaneous
B. Exothermic
C. Endothermic
D. Nonspontaneous
Answer:
the reaction is spontaneous
Raw material for rayon comes from
a.cellulose
b.coal
c.petroleum
d.animal bones
Explanation:
the raw material for the rayon come from is cellulose
If an atom has 32 protons in the nucleus, how many electrons will it have orbiting the nucleus
An atom is neutral as it has the same number of electrons that of protons. So, if an atom has 32 protons i.e. the atomic number of it is 32, then it will have 32 electrons revolving the nucleus.
What is the balance equation for
_ Ba + _ HNO3 —> _ H2 + _ Ba(NP3)2
_ H3PO4 + _ NaOH —> _ H2O + _ Na3PO4
1st one
2_2_2
2nd one
3_1_1_3
i looked it up
Someone plz help me here are the photos, I need the last one
Answer:
(6 mol)·(-393.5 kJ/mol) + (6 mol)·(-285.83 kJ/mol) - (1 mol)·(-1,273.02 kJ/mol) + (6 mol)·(0 kJ/mol)
Explanation:
Question; From the given options, the chemical reaction in the question is presented as follows;
C₆H₁₂O₆(s) + 6O₂(g) → 6CO₂(g) + 6H₂O(l), given that we have;
[tex]\Delta \text H _f^{\circ}[/tex] for C₆H₁₂O₆ = -1,273.02 kJ/mol
[tex]\Delta \text H _f^{\circ}[/tex] for O₂(g) = 0 kJ/mol
[tex]\Delta \text H _f^{\circ}[/tex] for CO₂(g) = -393.5 kJ/mol
[tex]\Delta \text H _f^{\circ}[/tex] for H₂O(l) = -285.83 kJ/mol
The heat or enthalpy of a reaction, is given as follows;
[tex]\Delta\text H_{rxn}^{\circ} = \sum \text n \cdot \Delta \text H _f^{\circ}(\text {products}) - \sum \text m \cdot \Delta \text H _f^{\circ}(\text {reactants} \text)[/tex]
Therefore, the equation which should be used to calculate [tex]\Delta\text H_{rxn}^{\circ}[/tex], is given as follows;
[tex]\sum \text n \cdot \Delta \text H _f^{\circ}(\text {products})[/tex] = (6 mol)·(-393.5 kJ/mol) + (6 mol)·(-285.83 kJ/mol)
[tex]\sum \text m \cdot \Delta \text H _f^{\circ}(\text {reactants} \text)[/tex] = (1 mol)·(-1,273.02 kJ/mol) + (6 mol)·(0 kJ/mol)
Therefore;
[tex]\Delta\text H_{rxn}^{\circ}[/tex] = (6 mol)·(-393.5 kJ/mol) + (6 mol)·(-285.83 kJ/mol) - (1 mol)·(-1,273.02 kJ/mol) + (6 mol)·(0 kJ/mol)
Help me please I really need this tomorrow
9.D
10.A
11.C
12.B
13.D
14.C
15.A
16.A
18.C
what is the formulas for Calcium Chloride,Aluminium Sulphate and Sodium hydroxide. *
Answer:
Explanation:
Why is there a star * behind the question.
CaCl2
Al2(SO4)3
NaOH
I need answers to question 1,2,3
Answer:
1. 0.125 mole
2. 42.5 g
3. 0.61 mole
Explanation:
1. Determination of the number of mole of NaOH.
Mass of NaOH = 5 g
Molar mass of NaOH = 23 + 16 + 1
= 40 g/mol
Mole of NaOH =?
Mole = mass /molar mass
Mole of NaOH = 5/40
Mole NaOH = 0.125 mole
2. Determination of the mass of NH₃.
Mole of NH₃ = 2.5 moles
Molar mass of NH₃ = 14 + (3×1)
= 14 + 3
= 17 g/mol
Mass of NH₃ =?
Mass = mole × molar mass
Mass of NH₃ = 2.5 × 17
Mass of NH₃ = 42.5 g
3. Determination of the number of mole of Ca(NO₃)₂.
Mass of Ca(NO₃)₂ = 100 g
Molar mass of Ca(NO₃)₂ = 40 + 2[14 + (3×16)]
= 40 + 2[14 + 48]
= 40 + 2[62]
= 40 + 124
= 164 g/mol
Mole of Ca(NO₃)₂ =?
Mole = mass /molar mass
Mole of Ca(NO₃)₂ = 100 / 164
Mole of Ca(NO₃)₂ = 0.61 mole
What are the effects of acid precipitation in city centers
Answer:
Answer to the following question is as follows.
Explanation:
Acid rain causes harm to houses and buildings by dissolving stone or corroding metal exposed to the elements. Acid rain can degrade calcium carbonate or calcium-based chemicals found in some of these products.
The acidic particles damage metal and accelerate the deterioration of paint and stone. They also make buildings and other structures, like as monuments, filthy.
During a process called photoact, ________ give up an electron as a part of the light-dependent reactions.
Answer:
Chloroplasts?
Explanation:
necesito que me ayuden a resolver lo de las imágenes por favor ... es urgente
A piece of solid tin is submerged in silver nitrate solution. A reaction occurs producing tin (iv) nitrate solution and solid silver. Write the word equation, write the skeletal equation and balanced chemical equation for the reaction.
Answer: For the given reaction-
The word equation is Tin + silver nitrate = tin (IV) nitrate + silverThe skeletal equation is [tex]Sn + AgNO_{3} \rightarrow N_{4}O_{12}Sn + Ag[/tex]The balanced chemical equation is [tex]Sn(s) + 4AgNO_{3}(aq) \rightarrow N_{4}O_{12}Sn(aq) + 4Ag(s)[/tex]Explanation:
When names of chemicals or species involved in a chemical reaction are represented in the form of an equation then it is known as a word equation.For example, Tin + silver nitrate = tin (IV) nitrate + silver
The 'equal to' symbol denotes a forward arrow.
A skeletal equation contains only the chemical formula of species involved in a chemical reaction.For example, [tex]Sn + AgNO_{3} \rightarrow N_{4}O_{12}Sn + Ag[/tex]
A chemical equation which contains same number of atoms on both reactant and product side along with states of species is called a balanced chemical equation.[tex]Sn(s) + 4AgNO_{3}(aq) \rightarrow N_{4}O_{12}Sn(aq) + 4Ag(s)[/tex]
A balloon at sea level on earth (1 atm pressure, 19°C) takes up 14.5 L of space. The balloon travels to Mars where atmospheric pressure is 4.55 torr and the temperature is -55°C What is the volume of the balloon on Mars?
Answer:
1807.24L
Explanation:
Using combined gas law equation:
P1V1/T1 = P2V2/T2
Where;
P1 = pressure on Earth
P2 = Pressure on Mars
V1 = volume on Earth
V2 = volume on Mars
T1 = temperature on Earth
T2 = temperature on Mars
According to the information provided of the balloon in this question;
P1 = 1 atm
P2 = 4.55 torr = 4.55/760 = 0.00599atm
V1 = 14.5L
V2 = ?
T1 = 19°C = 19 + 273 = 292K
T2 = -55°C = -55 + 273 = 218K
Using P1V1/T1 = P2V2/T2
1 × 14.5/292 = 0.00599 × V2/218
14.5/292 = 0.00599V2/218
Cross multiply
14.5 × 218 = 292 × 0.00599V2
3161 = 1.74908V2
V2 = 3161 ÷ 1.74908
V2 = 1807.24L
please let me know if this is correct?
Answer: Yes! you're all good. Alkali metals in group 1 are the most metallic :)
Which idea behind the shape of molecules includes the concept that electrostatic repulsion between electron pairs surrounding an atom causes these pairs to be separated as far as possible
Answer:
VSEPR theory
Explanation:
The valence shell electron pair repulsion theory was propounded by Gillespie and Nylom (1957).
The entire idea of the VSEPR theory is that the shape of a molecule depends on the electrostatic repulsion between electron pairs surrounding the central atom in a molecule which causes these pairs to be separated as far as possible.
The shapes of many molecules can be accurately predicted based on this model.
A 115.0-g sample of oxygen was produced by heating 400.0 g of potassium chlorate. 2KClO3 Right arrow. 2KCI 3O2 What is the percent yield of oxygen in this chemical reaction
Answer:
Percentage yield of O₂ = 73.4%
Explanation:
We'll begin by writing the balanced equation for the reaction. This is given below:
2KClO₃ —> 2KCl + 3O₂
Next, we shall determine the mass of KClO₃ that decomposed and the mass of O₂ produced from the balanced equation. This can be obtained as follow:
Molar mass of KClO₃ = 39 + 35.5 + (3×16)
= 39 + 35.5 + 48
= 122.5 g/mol
Mass of KClO₃ from the balanced equation = 2 × 122.5 = 245 g
Molar mass of O₂ = 2 × 16 = 32 g/mol
Mass of O₂ from the balanced equation = 3 × 32 = 96 g
SUMMARY:
From the balanced equation above,
245 g of KClO₃ decomposed to produce 96 g of O₂.
Next, we shall determine the theoretical yield of O₂. This can be obtained as follow:
From the balanced equation above,
245 g of KClO₃ decomposed to produce 96 g of O₂.
Therefore, 400 g 245 g of KClO₃ will decompose to produce
= (400 × 96)/245 = 156.7 g of O₂.
Thus, the theoretical yield of O₂ is 156.7 g
Finally, we shall determine the percentage yield of O₂. This can be obtained as follow:
Actual yield of O₂ = 115.0 g
Theoretical yield of O₂ = 156.7 g
Percentage yield of O₂ =?
Percentage yield = Actual yield /Theoretical × 100
Percentage yield = 115/156.7 × 100
Percentage yield = 11500/156.7
Percentage yield of O₂ = 73.4%
Energy transformation of a kettle?
Explanation:
Electrical energy into heat energy..hope it helps.stay safe healthy and happy...Nitrogen dioxide, a major air pollutant, can be produced by the combustion of nitrogen oxide as shown. 2NO + O2 Right arrow. 2NO2 In a plant, 1,500 kg of nitrogen oxide is consumed per day to produce 1,500 kg of nitrogen dioxide per day. What is the percent yield? Use Percent yield equals StartFraction actual yield over theoretical yield EndFraction times 100.. 21.7% 32.6% 43.5% 65.2% Mark this and return Save and Exit Next Submit
Answer:
65.2%
Explanation:
It is given that :
[tex]$2NO + O_2 \rightarrow 2NO_2$[/tex]
Therefore, 60 g of nitrogen oxide will produce 92 g of nitrogen dioxide
or 60 kg of nitrogen oxide will produce 92 kg of nitrogen dioxide
or 1500 kg of nitrogen oxide will produce [tex]2300\ kg[/tex] of nitrogen dioxide
Therefore the percentage yield = (Actual yield / Expected yield) x 100
percentage yield = [tex]$\frac{1500}{2300} \times 100$[/tex]
Percentage yield = 65.217 %
Answer:
the person above me is correct, the answer for this is 65.2% or option D!
Explanation:
thank you person above me! i got a 100% on the test! :D
Trends in the periodic table indicate that the element with the greatest ionization energy is in which of the following periods and groups?
a
Period 2, Group 1
b
Period 7, Group 2
c
Period 6, Group 17
d
Period 1, Group 18
Answer:
D Period 1, Group 18
Explanation:
it's helium
it's top right corner of the periodic table
