Answer:
the principal energy level of an electron refers to the shell or orbital in which the electron is located relative to the atoms nucleus. the first element in a period of the periodic table introduces a new principal energy level.
Explanation:
the electrons surrounding an atom are located in region around the nucleus called "energy level".
can someone please help me solve this? i dont understand this problem :(
Answer:
–4020 KJ
Explanation:
The following data were obtained from the question:
H₂(g) + F₂(g) —> 2HF(g) ΔH = –536 KJ
Next, we shall determine the mass of H₂ that reacted from the balanced equation to produce –536 KJ of heat energy. This can be obtained as follow:
Molar mass of H₂ = 2 × 1 = 2 g/mol
Mass of H₂ from the balanced equation = 1 × 2 = 2 g.
Summary:
From the balanced equation above,
2 g of H₂ reacted to produce –536 KJ of heat energy.
Finally, we shall determine the heat change produced by the reaction of 15 g of H₂. This can be obtained as follow:
From the balanced equation above,
2 g of H₂ reacted to produce –536 KJ of heat energy.
Therefore, 15 g of H₂ will react to produce = (15 × –536)/2 = –4020 KJ of heat energy.
Thus, the heat change for the reaction is –4020 KJ
In which highlighted section of the periodic table in the diagram provided above are the elements whose atoms have 1 valence electron located?
A) a
B) b
C) c
D) d
Answer:
B.
Explanation:
3. How many moles of H20 are in 15.2 grams of pure ice?
Answer:
18.01528 grams.
Explanation:
Ther are 0.84 moles of [tex]H_{2}O[/tex] in 15.2 g of pure ice.
The molar mass of [tex]H_{2}O[/tex] is 18g.
To calculate the number of moles of a substance in a given mass of the sample, we divide the given mass by the molar mass of the sample,
Number of moles = given mass / molar mass
It is given that we have 15.2g of pure ice. Then the number of moles of [tex]H_{2}O[/tex] will be:
n = 15.2/18
n = 0.84 moles.
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Which is the configuration of an atom in the ground state?
A)
2-8-2
B)
2-6-1
C)
2-7-2
D)
2-7-3
Answer:
Ground state means when n = 1
and here the electronic configuration is 2:8:2
how deficiency and excess of chromium
Answer:
The chromium found in foods will not hurt you. But taking excessive chromium supplements can lead to stomach problems and low blood sugar (hypoglycemia). Too much chromium from supplements can also damage the liver, kidneys, and nerves, and it may cause irregular heart rhythm.
What is the volume of a balloon that contains a 1.00 mol sample of oxygen with a pressure of 2.00 atm at 300.0 K?
Answer:
12.3
Explanation:
Trust
Ideal gas law is valid only for ideal gas not for vanderwaal gas. Therefore, 12.3L is the volume of a balloon that contains a 1.00 mol sample of oxygen with a pressure of 2.00 atm at 300.0 K.
What is ideal gas equation?Ideal gas equation is the mathematical expression that relates pressure volume and temperature. There is no force of attraction between the particles.
Mathematically the relation between Pressure, volume and temperature can be given as
PV=nRT
where,
P = pressure of oxygen gas= 2.00 atm
V= volume of oxygen gas =?
n =number of moles of oxygen gas=1.00 mol
T =temperature of oxygen gas =300.0 K
R = Gas constant = 0.0821 L.atm/K.mol
Substituting all the given values, we get
2.00×V=1× 0.0821×300.0
On calculation we get
Volume=12.3L
Therefore, the volume of oxygen is 12.3L.
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How many molecules are found in 60 grams of KOH?
Explain step by step please
Answer:
6.624× 10²³ molecules
Explanation:
Given data:
Mass of KOH = 60 g
Number of molecules = ?
Solution:
First of all we will calculate the number of moles.
Number of moles = mass/molar mass
Number of moles = 60 g/ 56.1 g/mol
Number of moles = 1.1 mol
Now number of molecules are determine by using Avogadro number.
1 mole = 6.022 × 10²³ molecules
1.1 mol × 6.022 × 10²³ molecules / 1mol
6.624× 10²³ molecules
Avogadro number:
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
For example,
18 g of water = 1 mole = 6.022 × 10²³ molecules of water
1.008 g of hydrogen = 1 mole = 6.022 × 10²³ atoms of hydrogen
what mass of carbon dioxide is produced from combustion of 100.0 grams of propane (C^3H^8)
Answer:
Mass of CO₂ produced = 299.64 g
Explanation:
Given data:
Mass of CO₂ produced = ?
Mass of propane (C₃H₈) = 100.0 g
Solution:
Chemical equation:
C₃H₈ + 5O₂ → 3CO₂ + 4H₂O
Number of moles of propane:
Number of moles = mass/molar mass
Number of moles = 100.0 g/ 44.1 g/mol
Number of moles = 2.27 mol
Now we will compare the moles of propane and carbon dioxide.
C₃H₈ : CO₂
1 : 3
2.27 : 3/1×2.27 = 6.81 mol
Mass of CO₂:
Mass = number of moles × molar mass
Mass = 6.81 mol × 44 g/mol
Mass = 299.64 g
whats the difference between a bonding electron domain and a nonbonding electron domain?
Answer: lone pair of electrons
Explanation: A bonding electron domain is a pair of electrons shared between two atoms and a nonbonding is a lone pair of electrons
The difference between the bonding electron domain and a nonbonding electron domain should be explained below.
Difference between bonding and non-bonding electron domain:A bonding electron domain refers to the region that lies between the two bonded atoms that comprise one or more pairs where the electrons should be bonded.
While on the other hand, the non-bonded electron contains on the single-atom also comprise of one pair of lone pair.
In this way, it should be differentiated.
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Although the order of elements is based on atomic number, vertical families share similar chemical properties.
Question 12 options:
True
False WHAT IS IT
Answer:
It's true
Explanation:
Uhhh, the internet! lol.
Answer:
It's true, ExplanationVVVExplanation: Because the order of elements is based on atomic number, vertical families share similar chemical properties.
Explain in a short sentence how you can tell if a reaction is a combustion reaction.
The reactants react with oxygen and there is energy formed.
Attempt 1
Question
You see Fred, a co-worker, not following safety procedures. What would be the best
thing to do?
A) nothing, as his safety is his own responsibility
B) pretend you didn't see him, but consider telling the boss
C) talk to him about putting his safety at risk
D) follow his example -- maybe the safety procedures are not necessary
Answer:
Would be C
Explanation:
helpig and bringing noice to a persons safety is always the right thing. C is correct, hope this helps
Do your answers to the previous questions satisfy
the following statements?
A) The dependent variable is changed by the
independent variable.
B) The independent variable causes a change
to another variable.
C) The independent variable is not changed by
another variable.
Answer:
I put B&C
Explanation:
Which statement describes a physical property to the particles that make up a material
Answer:
Gold is a relatively dense metal because its atoms have more
protons than atoms of many other metals.
Explanation:
What type of circuit is seen in the picture?
3 light bulbs and a battery connected with one loop of wire
Question 1 options:
series
AC
parallel
open
Answer:
C!!!!!!!!!!!!!!!!!!!!
Explanation:
Hope this helps!!!!!!!!!
I'm pretty sure it's a series circuit because all components are connected end-to-end, forming a single path for current flow.
PLEASE HELP When I combine Sprite with a sour candy, it starts to bubble a lot. Is this a physical or chemical change?
A. Physical Change
B. Chemical Change
Answer:
B. chemical
Explanation:
Chemical change cannot go back to its original form
Answer:
B
Explanation:
bubbles is a form of chemical change :)
Explain why you might feel ill after a vaccine
Answer:
Possibly a bad reaction as some people's immune systems are weaker than others
Explanation:
A sample of gas has a volume of 20.0 mL at STP. What will the volume be if the temperature is changed to 546 K and the pressure is changed to 2.0 atm.? (show work plz)
The volume did not change, it remained at 20 ml
Further explanationGiven
20 ml a sample gas at STP(273 K, 1 atm)
T₂=546 K
P₂=2 atm
Required
The volume
Solution
Combined gas Law :
[tex]\tt \dfrac{P_1.V_1}{T_1}=\dfrac{P_2.V_2}{T_2}[/tex]
Input the value :
[tex]\tt \dfrac{1\times 20}{273}=\dfrac{2\times V_2}{546}\\\\V_2=\dfrac{1\times 20\times 546}{273\times 2}\\\\V_2=20~ml[/tex]
The volume does not change because the pressure and temperature are increased by the same ratio as the initial conditions (to 2x)
do pressure and temputer remain consant in earth interior
Answer:
no
Explanation:
how many moles of silicon are in 5.9 X 10 to the 24 power atoms of silicon
Answer:
9.79740949850 moles
Explanation:
1 mole = Avogardo's Number <<6.022 E 23 <<particles, atoms, etc.>>This problem can be solved using dimensional analysis by multiplying atoms (5.9E24 atoms) by (1) mole and then dividing the number by Avogardo's number (6.022 E 23 atoms).Note: E = * 10Side Note: Please let me know if you need any clarifications about this!
Give two limitations of law of Constant Composition
Answer:
1.The law does not hold true if the different isotopes of the element are involved in making chemical compound.
2.The law is not applicable when elements combine in the same ratio but different compounds are formed.
How do you determine the charge of an ion?
Answer:
Subtract the number of electrons from the number of protons in an atom as a basic way of calculating the charge of the ion.
Explanation:
For example, if a sodium atom loses one electron, work out 11 - 10 = 1.
Which element has 7 valence electrons and 3 electron shells
Answer:
Halogens i think. hope this help
Explanation:
WHICH OF THE FOUR COMPOUNDS HAS BONDS WITH THE GREATEST DEGREE OF POLARITY (MOST POLAR)?
Answer:
I NEED TO KNOW THIS TOO
Explanation:
IVE BEEN LOOKING FOR THE ANSWER
A student mixes 20.0g of white KCl crystals with distilled water in a beaker. After the mixture was stirred, no crystals are visible and the solution is clear. After several days, all of the water evaporates and white crystals are found in the beaker. Which of following pieces of experimental evidence would best help the student to confirm that a new compound had not been made and that only a physical change occurred?
Answer:
After the water has evaporated, the white crystals in the beaker have a mass of 20.0g.
The pieces of experimental evidence would best help the student to confirm that a new compound had not been made and that only a physical change occurred is of 20.0 g of white KCl crystals.
What are physical changes?Physical changes are defined as a modification to a sample of material when some of the substance's attributes change but the composition of the sample remains the same. The digestion of food, combustion, osmosis, and phase transitions are just a few examples of how these changes play a crucial role in our daily lives.
Crystals are defined as a solid substance whose elements such as atoms, molecules, or ions are grouped in a highly organized microscopic structure to create an all-pervasive crystal lattice. Crystals are formed when molecules in a liquid group together to stabilize when it starts to cool and solidify.
Thus, the pieces of experimental evidence would best help the student to confirm that a new compound had not been made and that only a physical change occurred is of 20.0 g of white KCl crystals.
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Please actually help me.
Thank you!
Answer: I believe -3
Explanation:
8. __H2 + __O2-> __H2O
9. __K2SO4 + __H2-> __H2SO4 + __K
10. __NO2 + __H2O-> __HNO3 + __NO
Anser:
Explanation:
hope this helps
which element is unreactive and has a greater atomic radius than 1
Answer:
Atomic radii vary in a predictable way across the periodic table. As can be seen in the figures below, the atomic radius increases from top to bottom in a group, and decreases from left to right across a period. Thus, helium is the smallest element, and francium is the largest.
Select the correct answer from each drop-down menu.
Researchers stationed at different areas on a mountain and in a tunnel midway through the mountain boiled water at the same time. Even though the water at every station was at the same temperature, the pot at the top of the mountain started boiling before the others. Why?
Water boils when the vapor pressure is
the atmospheric pressure. The atmospheric pressure
at the top of the mountain.
Water boils when the vapour pressure is least the atmospheric pressure.
The atmospheric pressure is equal at the top of the mountain.
What is atmospheric pressure?The air around you has weight, and it presses against everything it touches. That pressure is called atmospheric pressure, or air pressure. It is the force exerted on a surface by the air above it as gravity pulls it to Earth.
As we go up in altitude the air pressure becomes less. When the pressure decreases, it takes less energy to get the water molecules to escape the surface. So the temperature is less than it would be at sea level.
Air pressure is higher or greater at the bottom of a mountain. This is because the height of the air above that level is thicker than at the top.
Pressure is given by the equation, P=rho*g*h, where rho is the air density, g is the gravity value and h is the thickness of the air layer on top of the level where we are considering the pressure.
Therefore, as we can see, at the bottom of the mountain, the thickness h of air is greater, and so is the pressure.
Hence, water boils when the vapour pressure is least the atmospheric pressure and the atmospheric pressure is equal at the top of the mountain.
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I really need your guys help, I need to pass.
Answer:
Question 4 is 291.0346
Explanation: