Answers
Answer: See below
Explanation: a. The mass of an element is composed of:
protons: 1 amu each
neutrons: 1 amu each
electrons: 0 amu each
Only the protons and neutrons are counted in the atomic mass of an element
b. Electrons are assigned a mass of 0. They do have a mass, but it is exceedingly small compared to the protons and neutrons, so they are left out of the calculation of an element's mass.
c. An element becomes unstable if the neutrons exceed the protons by a certain ratio, dependent on the element.
Related Questions
Which equation best represents the conservation of matter?
Answers
An image of Earth's layer is above.
Which layer is the most dense?
layer A
layer B
layer C
layer D
Answers
Answer:
d
Explanation:
il answer in comments if you brainly me
Sodium chlorate decomposes into sodium chloride and oxygen gas as seen in the equation below.
2NaClO3 --> 2NaCl +3O2
How many moles of NaCl were produced by 10 moles of NaClO3? Round your answer to the nearest whole number.
Answers
Answer:
10 moles of sodium chloride
Explanation:
[tex]\sf{}[/tex]
Which of the following resources can be obtained from the hydrosphere?
Answers
HOPE THIS HELPS YOU!!!!!
12) SEP Use Mathematics Complete the table by identifying the atomic number and
mass number for each atom and then using those data to determine the numbers
of protons, neutrons, and electrons.
Composition of Atoms
Atom
Atomic number
Mass number
Protons
Electrons
Neutrons
Na
2s
silver-108
47
T
gold-197
79
O
+ Back
Next →
INTL
Answers
The given elements are Na, Ag and Au.
1. Sodium(Na)
Mass number= 23 u
Atomic number=11
Number of protons= Number of electrons= Atomic number=11
Number of neutrons= Mass number- Number of protons=23-11=12
2. Silver (Ag)
Mass number= 108 u
Atomic number= 47
Number of protons= Number of electrons= Atomic number= 47
Number of neutrons= Mass number- Number of protons=108-47=61
3. Gold (Au)
Mass number= 197 u
Atomic number= 79
Number of protons= Number of electrons= Atomic number= 79
Number of neutrons= Mass number- Number of protons= 197-79=118
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Describe the five layers of the earth by providing the following information for each layer:
Name of the layer
Composition
Average temperature
Average thickness
make simple! pls
Answers
Answer:
answers below
Explanation:
Lithosphere/ Crust- made of large plates that move, average thickness is 30 km, average temperature is 25 degrees Celsius
Inner Core- made of solid iron, 1,200 km thick, 7,000 degrees Celsius
Outer Core- made of a dense liquid of iron and sulfur, 2,250 km thick, 4,000 degrees Celsius
Lower Mantle- made of solid rock, 2,200 km thick, 3,000 degrees Celsius
Asthenosphere/ Upper Mantle- made up of solid rock that flows due to plasticity, 720 km thick, 850 degrees Celsius
The (15-35-15) number on a bag of fertilizer is calculated by an outdated method. All modern fertilizers use PO43- as a source of phosphorus. Use your knowledge of the old methods to determine the moles of phosphorus found in 10.0 grams of (15-35-15)?
Answers
The (15-35-15) number on a bag of fertilizer is calculated by an outdated method. Using the knowledge of the old methods, the number of moles of phosphorus found in 10.0 grams of phosphorus is 0.05 mole.
The (15-35-15) number on the bag of fertilizer is used for:
Nitrogen 15 : Phosphorus pentoxide 35: potassium oxide 15Thus, in a 100-gram bag of fertilizer, there are 35 grams of phosphorus pentoxide P₂O₅.
∴
To determine the number of moles of 10 grams of phosphorus pentoxide in (15-35-15) bag of fertilizer, we have:
[tex]\mathbf{=10 \times \dfrac{35}{100} \ grams \ of \ P_2O_5}[/tex]
= 3.5 grams of P₂O₅
Recall that:
[tex]\mathbf{Number of moles = \dfrac{mass}{molar \ mass}}[/tex]
the molar mass of P₂O₅ = 142 g/mol∴
[tex]\mathbf{Number of moles = \dfrac{3.5\ g}{ 142 \ g/mol}}[/tex]
[tex]\mathbf{Number of moles = 0.0246 \ mol}[/tex]
Provided that 1 mole of P₂O₅ harbors 2 moles of phosphorus;
Then;
The number of phosphorus present in 10.0 grams of (15-35-15) fertilizer is:
= 0.0246 moles × 2
= 0.0492 moles
≅ 0.05 moles
Therefore, we can conclude that the number of moles of phosphorus found in 10.0 grams of (15-35-15) bag of fertilizer is 0.05 moles.
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3. Which statements are true based on the Bohr model of the atom? Select all that
apply.
encore
a. Atomic emission spectra are due to electrons losing energy and changing
energy levels
b. The energy of transition for n=3 to n=4 would be the same as n=5 to n=6
c. The first energy level is set at zero energy
d. Electrons lose energy as they travel around the nucleus
e. Each energy level has a specific energy value
Answers
The model of Neils Bohr postulates that electrons in atoms are found in specific energy levels. Transition from a higher to a lower energy level produces an emission spectrum characteristic of elements.
According to Bohr's model of the atom, an electron in atom exists in distinct energy levels. Electrons can be promoted from lower to higher energy levels when they absorb energy. The electrons are unstable in this higher energy excited state hence they quickly return to the ground state emitting energy. This emission is characteristic of elements.
The following statements are true based on the Bohr model;
Atomic emission spectra are due to electrons losing energy and changing energy levels.Each energy level has a specific energy valueLearn more: https://brainly.com/question/24556237
Write the equation for the alpha decay of C-11.
Write the equation for the beta decay of Be-10
HELP HELP HELP
Answers
Answer:
We know that in the decay process the sum of molecular number as well as molecular weight should be constant.
The following three reaction are as follows
1 .
Explanation:
How many moles of KBr are present in 180. mL of a 0.108 M solution?
Express the amount in moles to three significant digits.
Answers
by molality you can find the mole
Convection currents in the atmosphere influence many weather patterns. What property of the air has the most influence on convection currents?
1. The direction of the wind
2. The velocity of the wind
3. The temperature of the air
4. The mass of the air
Answers
Convection currents are largely influenced by air temperature. A low-pressure area is produced when air is heated because it becomes less dense and rises.
What effect on the climate does convection have?For instance, the air above the Earth heats and rises as its surface warms from the sun. This air may continue to rise while cooling and producing cumulus clouds if the conditions allow.
How do air masses respond to convection currents?Climate-affecting wind patterns are driven by convection currents. Convection currents are used to shift air masses. There are two different kinds of air masses: warm and cold. From higher latitudes to lower latitudes, cold air masses travel.
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Part A
Enter an equation for the precipitation reaction that occurs (if any) when solutions of ammonium chloride and calcium nitrate are mixed.
Express your answer as a chemical equation. Identify all of the phases in your answer. Enter noreaction if no precipitate is formed.
ΑΣΦ
?
2NH, Cl(aq) + Ca(NO3)2 (aq) +CaCl, (s) + 2N, O(g) + 4H, O(g)
DA chemical reaction does not occur for this question
Submit
Previous Answers Request Answer
X Incorrect; Try Again; One attempt remaining
Provide feedback
Answers
The equation of reacting ammonium chloride with calcium nitrate will be: [tex]Ca(NO3)_2(s) + 2NH_4CI(s) --- > 2N_2O(g) + CaCl_2(s) + 4H_2O(g)[/tex]
What are chemical reactions?They are reactions involving chemical reactants.
Ammonium chloride, in solid form, will react with calcium nitrate, also in solid form to produce dinitrogen oxide gas, solid calcium chloride, and water vapor.
The equation of the reaction is represented as follows:
[tex]Ca(NO3)_2(s) + 2NH_4CI(s) --- > 2N_2O(g) + CaCl_2(s) + 4H_2O(g)[/tex]
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MARKING BRAINLIEST!
Which of the following best defines velocity?
It is an object's speed at a specific point in time.
It is the total distance traveled over the total time.
It is the speed of an object in a specific direction.
It is a measure of how far an object moves in a certain time.
Answers
Answer:
3
Explanation:
The velocity is basically the speed + the direction of an object put into one quantity, velocity.
hope this helps, if not see me in the comments...
HOPE THIS HELPS BRAINLIEST PLZZ
what is the common and IUPAC name for Oxygen?
Answers
Answer:
International Union of Pure and Applied Chemistry (IUPAC) justified ways how to name organic compounds [ hydrocarbons ].
Oxygen has only a molecular name which is dioxide
Please help me with the following question below:
Answers
Molarity as Stoikiometri
Level : SHSEquatuions od Molarity :
M = m/Mr × 1000/V
Mr Lithium Dichromate (Li2CrO4)
= Ar Li (2) + Ar Cr + Ar O (4)
= 7 (2) + 52 + 16 (4)
= 14 + 52 + 64
= 130 g/mol
Molarity
= m/Mr × 1000/V
= 19.5 g/130 g/mol × 1000/95 mL
= 0.15 mol × 10.53 /L
= 1.5795 mol/L
So, the molarity of the solution is 1.5795 mol/L
#LearnWithEXO
Which of these is a function of all cells ?
A. To produce oxygen through photosynthesis
B. To combine with other cells to form tissues
C. To subdivide to form cells for sexual reproduction
D. To transfer genetic information from one generation to the next
Answers
Answer:
a because it help in protecting disease
2 H2O(l) → 2 H2 (g) + O2 (g) ΔH°rxn = +572 kJ Determine the heat associated with the reaction (qrxn, in kJ) when 4.85 grams of H2(g) is produced.
Answers
The heat associated with the reaction (qrxn, in KJ) when 4.85 grams of H₂ is produced is +693.55 KJ
Balanced equation2H₂O → 2H₂ + O₂ ΔH°rxn = +572 KJ
Molar mass of H₂ = 2 × 1 = 2 g/mol
Mass of H₂ from the balanced equation = 2 × 2 = 4 g
SUMMARY
From the balanced equation above,
When 4 g of H₂ is produced, 572 KJ of heat where needed.
How to determine the heat requiredFrom the balanced equation above,
When 4 g of H₂ is produced, 572 KJ of heat where needed.
Therefore,
When 4.85 g of H₂ is produced = (4.85 × 572) / 4 = +693.55 KJ of heat will be required.
Thus, +693.55 KJ of heat is required for the reaction.
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Covalent bonds take place between..
A. A metal and a nonmetal
B. A metal and a metalloid
C. Two nonmetals
D.two metals
please answer this question. No links please!!!
Answers
Answer:
Covalent Bonds are formed when two non-metals share electrons
Hope this helps
37. A patient had pale tinger nail, shortness of breath and felt dizzy. The patient is most likely suffering from A. Kwashiorkor B. Marasmus C. Anaemia D. Rickets
Answers
Answer:
Anaemia
Explanation:
Symptoms: fatigue, skin pallor, shortness of breath, lightheadedness, dizziness, or a fast heartbeat.
please help me solve this
Answers
Answer:
dude your handwriting!!!
Question 5 of 5
Which idea was not supported by Dalton's atomic model but was supported in
all later atomic models?
A. A central, positive nucleus
B. Electrons in orbits
C. Positive and negative parts
D. Electron clouds
Answers
Answer:
It’s A
The indivisibility of an atom was proved wrong: an atom can be further subdivided into protons, neutrons and electrons. However an atom is the smallest particle that takes part in chemical reactions. According to Dalton, the atoms of same element are similar in all respects.
Which location in the diagram above is the Southern Hemisphere experiencing summer?
Location A
Location B
Location C
Location D
Answers
Answer:
location a
Explanation:
Answer:
Location B
Explanation:
HELP PLS WILL NAME BRANLIEST BUT No LiNkS jUsT helP No LiNkS
Answers
Answer:
I think it's A and C. Please tell me if I am wrong.
Explanation:
Answer:
Alright so I did this quiz a while ago it's A and C now could i have brainliest?
Explanation:
Moon rocks resemble rocks from which of the following layers of the earth?
Answers
It’s the mantle
Explanation:
Just cause . Hope this helps and tell me if im wrong.
11. A cart is loaded with a brick and pulled at constant speed along an inclined plane to the height of a seat-top. If the
mass of the loaded cart is 3,500g and the height of the seat top is 0.45 meters, then what is the potential energy of the
loaded cart at the height of the seat-top?
Answers
Answer:
15.75 J
Explanation:
Potential energy
= mgh
= 3,500 g × 10 m/s² × 0.45 meters
= 3.5 kg × 4.5 m²/s²
= 15.75 J
which of the following terms completes the sentence below? to fill out a sign chart, you will need to use test numbers before and after each of the functions zeros and ___? A asympototes B expressions C proportions D values
Answers
HELP!! please choose all the correct answers, picture attached
Answers
A solution made from pure Potassium hydroxide contained 1.85 g of Potassium hydroxide in exactly 200 cm3 of water. Using phenolphthalein indicator, titration of 20.0 cm3 of this solution is carried out v/s sulphuric acid. 9.35 cm3 of sulphuric acid solution is required for complete neutralisation. [atomic masses: K= 39, O = 16, H = 1]
(a) write the equation for the titration reaction.
(b) calculate the molarity of the Potassium hydroxide solution. (c) calculate the moles of Potassium hydroxide neutralised. (d) calculate the moles of sulphuric acid neutralised.
(e) calculate the molarity of the sulphuric acid.
Answers
The concentration of H2SO4 is 0.176 M. The number of moles of H2SO4 is 0.0165 moles.
The equation of the reaction is;
2KOH(aq) + H2SO4(aq) ------> K2SO4(aq) + H2O(l)
The number of moles of KOH = 1.85 g/56 g/mol = 0.033 moles
concentration = number of moles /volume
volume = 200 cm3 or 0.2 L
concentration of KOH = 0.033 moles/0.2 L = 0.165 M
From the titration formula;
CAVA/CBVB =na/nb
CA = concentration of acid
VA = volume of acid
CB = concentration of base
VB = volume of base
na = number of moles of acid
nb = number of moles of base
Making CA the subject of formula;
CA = CBVBna/VAnb
CA = ?
CB = 0.165 M
VA = 9.35 cm3
VB = 20.0 cm3
na = 1
nb =2
CA = CBVBna/VAnb
CA = 0.165 M × 20.0 cm3 × 1/9.35 cm3 × 2
CA = 0.176 M
The concentration of sulphuric acid is 0.176 M
From the reaction equation;
2 moles of KOH reacts with 1 mole of H2SO4
0.033 moles of KOH reacts with 0.033 moles × 1 mole/2 moles
= 0.0165 moles of H2SO4
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Q13. Which of the following is a balanced chemical equation for the reaction between potassium carbonate soletion and hyelrochlori acid. 1
Answers
Answer:
Below
Explanation:
2HCl + K2CO3 -> 2KCl + CO2 + H2O
how do i convert 9.5125 liters to gallons
Answers
Answer:
That would be 2.51293615
Explanation:
1 liter is equal to 0.264172 gallons.
What you would need to do is, multiply the total number of liters, which in this case is 9.5125, by 0.264172.
9.5125 x 0.264172 gets you 2.51293665.
I hope this helps! :)
