What is true of valence electrons?
Question 14 options:
They exist in the outer orbital.
They have difficulty moving from one orbital to another.
They are always the lowest energy electrons of the atom.
They easily move from one orbital to anothe
Answer:They exist at specific energy levels.
Explanation:
What is the energy of a photon of green light whose frequency is 6.85 X 1014/seC?
I would be very thankful if I can receive the answer fast
Frequency of photon = is 6.85 X 10¹⁴ sec⁻¹
Energy of photon , E = hv
where h is Planck's constant, v is the frequency of photon
E = 6.63 × 10⁻³⁴ J.s x 6.85 X 10¹⁴ s⁻¹
E = 4.54 x 10⁻¹⁹ J
Therefore, the energy of a photon of green light is 4.54 x 10⁻¹⁹ J.
how are ionic bonds formed? a. by the disintegration of one or more electronsb. by the sharing of one or more electrons between two atomsc. by the transfer of one or more electrons from one atom to anotherd. by the disintegration of one or more protons
The correct answer is: by the transfer of one or more electrons from one atom to another.
Express in scientific notation. Choose the answer with the proper number of significant figures. (3 x 104) (4 x 1023) = _____ 1227 12 x 1027 10 x 1027 1 x 1028
You know what number of significant figures is required by what they give you originally. In this case, there is only one. (3x10^4)(4x10^23) = 1.2x10^28. However, this is the answer with two significant figures. Thus, round it to become one sigfig: 1x10^28.
Answer:
1x10^28
Explanation:
If many observations or results of experiments fail to agree with your deductive reasoning, then:
the general principle or theory is probably false.
the general principle or theory is probable true.
the general principle or theory is probably false
The compound copper(ii) nitrate is a strong electrolyte. write the reaction when solid copper(ii) nitrate is put into water:
When solid copper(II) nitrate is dissolved in water, it breaks down into copper(II) ions and nitrate ions. This process is represented by the balanced chemical equation: Cu(NO3)2 (s) -> Cu^2+ (aq) + 2 NO3^- (aq).
Explanation:When solid copper(II) nitrate, denoted as Cu(NO3)2, is put into water, it dissociates into its ions. The balanced chemical reaction is represented as follows:
Cu(NO3)2 (s) -> Cu^2+ (aq) + 2 NO3^- (aq)
Here, (s) stands for solid, while (aq) means aqueous, i.e., ions dissolved in water. Copper(II) nitrate breaks down into copper(II) ions (Cu^2+) and nitrate ions (NO3^-). Because copper(II) nitrate is a strong electrolyte, it dissociates completely in water, meaning there are no leftover solid particles floating in the solution, just a solution of the individual ions.
Learn more about Dissociation of Copper(II) Nitrate here:https://brainly.com/question/29402119
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3. Classify each of the following materials as a pure substance or mixture. If it is a pure substance, indicate if it is an element or a compound. If it is a mixture, indicate if it is a homogeneous mixture or heterogeneous. (2 points each)
Questions
1.
The copper in a copper wire
2.
Gatorade
3.
Chocolate chip ice cream
4.
Sugar (C12H22O11)
5.
Glitter nail polish
6.
Diamond (C)
7.
Salt (NaCl)
8.
Air
9.
Helium gas
10.
Carbon dioxide gas
11.
Coffee
12.
Caffeine (C8H10N4O2)
13.
Tomato soup
14.
Chicken noodle soup
15.
Brass
16.
Pure water
17.
Pure iron
18.
Sweat
19.
Baking soda (NaHCO3)
Classify each of the following materials as a pure substance or mixture. If it is a pure substance, indicate if it is an element or a compound. If it is a mixture, indicate if it is a homogeneous mixture or heterogeneous. (2 points each)
Questions
1.
The copper in a copper wire pure
2.
Gatorade heterogeneous
3.
Chocolate chip ice cream heterogeneous
4.
Sugar (C12H22O11) pure
5.
Glitter nail polish heterogeneous
6.
Diamond (C) pure
7.
Salt (NaCl) pure
8.
Air homo
9.
Helium gas pure
10.
Carbon dioxide gas pure
11.
Coffee depends on being black and unsaturated
12.
Caffeine (C8H10N4O2) pure
13.
Tomato soup heterogeneous
14.
Chicken noodle soup heterogeneous
15.
Brass homo
16.
Pure water pure
17.
Pure iron pure
18.
Sweat homo
19.
Baking soda (NaHCO3) pure
Final answer:
Detailed classification of substances as pure substances or mixtures, elements or compounds, and homogeneous or heterogeneous mixtures.
Explanation:
A pure substance either consists of a single type of atom, an element, or of molecules made from atoms of two or more types bound together, known as compounds. Mixtures can be either homogeneous, where the composition is consistent throughout, or heterogeneous, where the substances that make up the mixture are not evenly distributed. The items can be classified as -
1. The copper in a copper wire: Pure substance - Element
2. Gatorade: Mixture - Homogeneous
3. Chocolate chip ice cream: Mixture - Heterogeneous
4. Sugar (C12H22O11): Pure substance - Compound
5. Glitter nail polish: Mixture - Heterogeneous
6. Diamond (C): Pure substance - Element
7. Salt (NaCl): Pure substance - Compound
8. Air: Mixture - Homogeneous
9. Helium gas: Pure substance - Element
10. Carbon dioxide gas: Pure substance - Compound
11. Coffee: Mixture - Homogeneous
12. Caffeine (C8H10N4O2): Pure substance - Compound
13. Tomato soup: Mixture - Homogeneous
14. Chicken noodle soup: Mixture - Heterogeneous
15. Brass: Mixture - Homogeneous
16. Pure water: Pure substance - Compound
17. Pure iron: Pure substance - Element
18. Sweat: Mixture - Homogeneous
19. Baking soda (NaHCO3): Pure substance - Compound
Examine the information.
A runner travels 10 m/s forward for 10 seconds.
Which of the quantities in the sentence would be considered a vector quantity, and why?
The quantity 10 m/s is the only vector quantity because it is a measurement of speed.
The quantity 10 s is the only vector quantity because it measures time.
The quantity 10 m/s is the only vector quantity because it is a measurement that includes a direction.
The quantities 10 m/s and 10 s are vector quantities because these numbers are both measurements that do not include direction.
Answer:
The quantity 10 m/s is the only vector quantity because it is a measurement that includes a direction.
Explanation:
Vector quantities are physical quantities with both magnitude (size) and direction. Examples of vectors include displacement, velocity, acceleration, force, momentum etc.
Time is a scalar quantity having only size. So 10 s is not a vector. 10 m/s forwards is velocity because of the direction.
Read the scenario.
A lizard is at an initial position of 2 m and walks to a position of 10 m in 4 s.
What is the lizard’s average velocity?
2.5 m/s
-3 m/s
2 m/s
3 m/s
The answer is C. 2 m/s
Answer: 2m/s
Explanation:
Initial position = 2m
Final position = 10m
Distance = 10-2 = 8m
Time = 4s
Velocity = distance(m) /time(s)
Velocity = 8/4 = 2m/s
Recorded observations are called:
data
information
impressions
feelings
ideas
What is one characteristic of the groundwater that forms caves? A. It is very hot. B. It is very cold. C. It is slightly acidic. D. It is slightly basic.
Answer: Groundwater that forms caves because it is slightly acidic.
Explanation:
The water under the ground present inside the cracks and spaces in sand, soil and rocks is called ground water.
When ground water moves through the soil it results in the formation of acid. Further, this acid helps minerals to get dissolve. These minerals get deposited on other places as well.
This process of deposition and erosion helps in the formation of caves.
Thus, it can be concluded that groundwater that forms caves because it is slightly acidic.
Which of these four liquids is a mixture, made up of parts, some of which can be separated by flirtation? a. Salt water b. Skimmed milk c. Orange juice with pulp d. Distilled water
Orange juice with pulp is the correct answer because it is a heterogeneous mixture with suspended particles that can be separated by filtration.
Explanation:The question asks to identify which of the four liquids listed is a mixture that can be separated by filtration. Among the options provided:
Salt water is a homogeneous mixture, known as a solution, where the salt is completely dissolved in the water and cannot be separated by filtration.Skimmed milk is a colloid where the particles are larger than those in a solution but remain dispersed and do not settle, and thus also cannot be easily separated by filtration.Orange juice with pulp is a heterogeneous mixture that has suspended particles (pulp) which can be separated through filtration.Distilled water is not a mixture at all but a pure substance with a uniform and definite compositionTherefore, the liquid that is a mixture and can have some of its parts separated by filtration is orange juice with pulp.
12. What volume of carbon dioxide contains the same number of molecules as 20.0 mL of oxygen at the same conditions?
Which one of the following mixtures is classified as a suspension
Final answer:
A suspension is a heterogeneous mixture where the dispersed particles are large enough to settle upon standing. Mud in water is an example of a suspension because it has large particles that are visible, the mixture is cloudy, and particles settle when undisturbed.
Explanation:
To identify which mixture is classified as a suspension, it's essential to understand the particle sizes involved in different mixtures. A suspension contains particles with diameters around 1 µm (1000 nm) that are dispersed throughout another phase. Examples of suspensions include muddy water and paint. In contrast, colloids involve much smaller particles (2 to about 500 nm in diameter) that do not settle on standing, such as milk or fog.
Considering the information provided, a suspension is a heterogeneous mixture where the dispersed particles are large enough to settle out upon standing. These particles can often be separated from the dispersing medium by filtration. In contrast, a solution has much smaller particles that do not settle and cannot be filtered out.
From the examples provided, mud in water fits the definition of a suspension. The particles are of appropriate size, it's heterogeneous, the mixture is cloudy due to the particles, and it will allow for settling over time if left undisturbed.
What is the molarity of 820 ml of kl solution that contains 36.52 g of kl
The formula is molarity (M) = moles / liters
molarity (M) = ?
1/ mass = 36.52 g of KCl (you need to find the mole)
mole = mass / Molar mass
Molar mass of KCl:
K = 39.10 g/mol
Cl = 35.45 g/mol
Add K and Cl together: 39.10 + 35.45 = 74.55 g/mol
mole = 36.52 g of KCl / 74.55 g/mol
mole = 0.489 mol of KCl
2/ Volume = 820 mL ( you need to convert to L)
820 / 1000 = 0.82 L
=> M = mol / L
M = 0.489 mol / 0.82 L
M = 0.59 mol/L
Hope this help!
Answer: 0.27 M
Explanation:
Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution.
[tex]Molarity=\frac{n\times 1000}{V_s}[/tex]
where,
n = moles of solute
To calculate the moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}=\frac{36.52g}{166g/mol}=0.22moles[/tex]
[tex]V_s[/tex] =volume of solution in ml
Molarity =[tex]\frac{0.22\times 1000}{820ml}=0.27M[/tex]
The molarity of the solution is 0.27 M.
About 300 B.C., Aristarchus suggested that the sun was at the center of the universe. Why?
The brightness of the planets would change.
The planets appeared to move among the constellations.
The planets always moved opposite to the stars.
The planets disappeared periodically.
The correct answer is option A and B
About 300 B.C., Aristarchus suggested that the sun was at the center of the universe because a) the brightness of the planets would change and b) the planets appeared to move among the constellations.
18 centuries before Copernicus, Aristarchus predicted that all planets orbit the sun. In other words, he suggested the Solar System is heliocentric.
Answer:
the answer is A And B
Explanation:
just took the test
what is the concentration of a NaCl solution, in Molarity, if you add 59.76 g of NaCl into 270 mL of H2O
Hey there!
Molar mass NaCl = 58.44 g/mol
Number of moles
n = mass of solute / molar mass
n = 59.76 / 58.44
n = 1.0225 moles of NaCl
Volume in liters:
270 mL / 1000 => 0.27 L
Therefore:
M = number of moles / volume ( L )
M = 1.0225 / 0.27
= 3.78 M
Hope that helps!
Protons are positively charged and repel other protons. Which order particle is found in the nucleus and separates protons so that the strong force can hold the nucleus together?
Mole Word Problems
The recommended daily allowance of selenium in your diet is 6.97x10-7 mole. How many atoms of selenium is this?
A bracelet containing 0.200 mol metal is 75% gold. How many atoms of gold are in the bracelet?
Which has more atoms, 10.0 g C or 10.0 g of Ca? How many atoms does each contain?
A mixture contains 0.250 mol Fe and 1.20 g C. What is the total number of atoms in the mixture?
Air contains several gases. Argon makes up 0.934% of the air. If a person takes a breath that contains 0.600 g of air, calculate the number of argon atoms inhaled.
A chemist needs 0.015 mol of iodine crystals, I2, for an experiment. What mass of iodine crystals should the student obtain?
BONUS PROBLEM
One atom of an unknown element has a mass of 6.66x10-23 g. What is the identity of this element?
Q: The recommended daily allowance of selenium in your diet is 6.97x10-7 mole. How many atoms of selenium is this?
Answer:4.19 × 10¹⁷ Se Atoms
Solution:As we know that 1 mole of any substance contains exactly 6.022 × 10²³ particles which is also called as Avogadro's Number. So in order to calculate the number of particles (atoms) contained by 6.97 × 10⁻⁷ moles of Se, we will use following relation,
Moles = Number of Atoms ÷ 6.022 × 10²³ Atoms.mol⁻¹
Solving for Number of Atoms,
Number of Atoms = Moles × 6.022 × 10²³ Atoms.mol⁻¹
Putting values,
Number of Atoms = 6.97 × 10⁻⁷ mol × 6.022 × 10²³ Atoms.mol⁻¹
Number of Atoms = 4.19 × 10¹⁷ Atoms
++++++++++++++++++++++++++++++++++++++++++++++++++
Q: A bracelet containing 0.200 mol metal is 75% gold. How many atoms of gold are in the bracelet?
Answer:9.033 × 10²² Atoms of Gold
Solution:As we know that 1 mole of any substance contains exactly 6.022 × 10²³ particles which is also called as Avogadro's Number. So in order to calculate the number of particles (atoms) contained by 0.200 moles of Au, we will use following relation,
Moles = Number of Atoms ÷ 6.022 × 10²³ Atoms.mol⁻¹
Solving for Number of Atoms,
Number of Atoms = Moles × 6.022 × 10²³ Atoms.mol⁻¹
Putting values,
Number of Atoms = 0.200 mol × 6.022 × 10²³ Atoms.mol⁻¹
Number of Atoms = 1.20 × 10²³ Atoms
For 75%,
Number of Atoms = 1.20 × 10²³ Atoms × 0.75
Number of Atoms = 9.033 × 10²² Atoms of Gold
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Q: Which has more atoms, 10.0 g C or 10.0 g of Ca? How many atoms does each contain?
Answer:Carbon has greater number of Atoms.
Solution:Data Given:
Mass of Carbon = 10 g
M.Mass of Carbon = 12.01 g.mol⁻¹
Mass of Calcium = 10 g
M.Mass of Calcium = 40.08 g.mol⁻¹
Step 1: Calculate Moles of Carbon as,
Moles = Mass ÷ M.Mass
Putting values,
Moles = 10 g ÷ 12.01 g.mol⁻¹
Moles = 0.8326 mol
Step 2: Calculate number of Carbon atoms,
As 1 mole of any substance contains 6.022 × 10²³ particles (Avogadro's Number) then the relation for Moles and Number of Carbon atoms can be written as,
Moles = Number of C Atoms ÷ 6.022 × 10²³ Atoms.mol⁻¹
Solving for Number of C atoms,
Number of C atoms = Moles × 6.022 × 10²³ Atoms.mol⁻¹
Putting value of moles,
Number of C atoms = 0.8326 mol × 6.022 × 10²³ Atoms.mol⁻¹
Number of C atoms = 5.01 × 10²³ C atoms
Step 3: Calculate Moles of Calcium as,
Moles = Mass ÷ M.Mass
Putting values,
Moles = 10 g ÷ 40.08 g.mol⁻¹
Moles = 0.25 mol
Step 4: Calculate number of Calcium atoms,
As 1 mole of any substance contains 6.022 × 10²³ particles (Avogadro's Number) then the relation for Moles and Number of Calcium atoms can be written as,
Moles = Number of Ca Atoms ÷ 6.022 × 10²³ Atoms.mol⁻¹
Solving for Number of Ca atoms,
Number of Ca atoms = Moles × 6.022 × 10²³ Atoms.mol⁻¹
Putting value of moles,
Number of Ca atoms = 0.25 mol × 6.022 × 10²³ Atoms.mol⁻¹
Number of Ca atoms = 1.50 × 10²³ C atoms
++++++++++++++++++++++++++++++++++++++++++++++++++
Q: A mixture contains 0.250 mol Fe and 1.20 g C. What is the total number of atoms in the mixture?
Answer:2.10 × 10²³ Atoms in Mixture
Solution:Atoms in Fe:
As we know that 1 mole of any substance contains exactly 6.022 × 10²³ particles which is also called as Avogadro's Number. So in order to calculate the number of particles (atoms) contained by 0.25 moles of Fe, we will use following relation,
Moles = Number of Atoms ÷ 6.022 × 10²³ Atoms.mol⁻¹
Solving for Number of Atoms,
Number of Atoms = Moles × 6.022 × 10²³ Atoms.mol⁻¹
Putting values,
Number of Molecules = 0.25 mol × 6.022 × 10²³ Atoms.mol⁻¹
Number of Molecules = 1.50 × 10²³ Atoms of Fe
Atoms in C:
Step 1: Calculate Moles of Carbon as,
Moles = Mass ÷ M.Mass
Putting values,
Moles = 1.20g ÷ 12.01 g.mol⁻¹
Moles = 0.0999 mol
Step 2: Calculate number of Carbon atoms,
As 1 mole of any substance contains 6.022 × 10²³ particles (Avogadro's Number) then the relation for Moles and Number of Carbon atoms can be written as,
Moles = Number of C Atoms ÷ 6.022 × 10²³ Atoms.mol⁻¹
Solving for Number of C atoms,
Number of C atoms = Moles × 6.022 × 10²³ Atoms.mol⁻¹
Number of C atoms = 0.0999 × 6.022 × 10²³ Atoms.mol⁻¹
Number of C atoms = 6.01 × 10²² C Atoms
Total Number of Atoms:
= 6.01 × 10²² C Atoms + 1.50 × 10²³ Atoms of Fe
= 2.10 × 10²³ Atoms in Mixture
Remaining answers are attached.
Most people like to go outside on a sunny day, but too much sun exposure can cause sunburns as well as long term health problems, such as eye damage or skin cancer. How do humans protect themselves from too much sun exposure?
Answer:
all of these
Answer:
all of these
Explanation:
Which is a raw material necessary for photosythisies.
water and carbon dioxide
50 POINTS!!! Based on your observations in the virtual lab, fill in the data table below.
Question 2 options:
Separated using a filter; magnetism
Separated using a magnet; malleability
Separated using filtration; conductivity
Separated using a magnet; magnetism
Hi Khal75,
Experiment: How to seperate iron fillings
Iron fillings is a substance that attracts to magnets.
Answer - Separated using a magnet; magnetism
If you move a magnet around different solids with the iron fillings in it, it wil attract the iron to be able to seperate it.
The requirements of atoms to be able to participate in hydrogen bonding with a hydrogen atom include
all of the following except
A. atoms must have one lone pair of electrons.
B. atoms must be electronegative.
C. atoms must be small.
D. atoms must not be able to closely approach the hydrogen.
Answer: C. atoms must be small.
Explanation: Hydrogen bond is the result of the electrostatic forces of attraction between the hydrogen and the electonegative atom. It is a type of dipole dipole interaction which is not so much of a covalent bond.
The options A, B and D satisfies the definition of the hydrogen bonding but the option C seems to be irrelevant as hydrogen bonding does not deal with the size of the atom.
Thus for the hydrogen bonding , the other atom must be electronegative, and atoms must have atleast one lone pair of electrons and atoms must not be able to closely approach the hydrogen.
A fertilizer is 60.9% ammonium phosphate. What is the percent P in the sample? Answer in units of %
I originally got 20.7685% but it says my answer is wrong. Help?
Answer:- 12.7%
Solution:- It says, ammonium phosphate is 60.9%. It means if we assume 100 g of the sample then there is 60.9 g ammonium phosphate in it.
Formula of ammonium phosphate is [tex](NH_4)_3PO4[/tex] and it's molecular weight is 149 grams per mol. There is only one P in the formula and so the mass of P in 149 g of ammonium phosphate is 31 g(atomic mass of P).
Now, we could use the proportions to find out the mass percentage of P in the sample.
31 g P is present in 149 g of ammonium phosphate, how many grams of P would be present in 60.9 g of ammonium phosphate. Let's set the proportions as:
[tex]\frac{31}{149}=\frac{x}{60.9}[/tex]
[tex]x=\frac{31(60.9)}{149}[/tex]
[tex]x=12.7[/tex]
This 12.7 g of phosphorous is present in 100 g of the sample means there is 12.7% phosphorous in the sample.
Electron configuration for Lithium.
The answer to problem is [He] 2s1. Hope it helps
Your answer is [He] 2s1
Hope that helps :)
How do you turn a proportionality between variables into an equation?
Answer. By adding the proportionality constant .
Explanation:
suppose 'x' a is directly proportional to the 'y' , where x and y are variables:
x ∝ y
with an input of constant value 'K' proportionality relation gets converted into an equation:
x = K y
For example : Gravitational force is directly proportional to the product of two masses and inversely proportional to the square of the distance between the two masses.
F ∝ [tex]\frac {m_1m_2}{r^{2}}[/tex]
To convert this proportionality relation constant 'G' was introduced known as gravitational constant whose value remains constant under every conditions.
[tex]F=\frac {G\times m_1m_2}{r^{2}}[/tex]
[tex]G=6.67408\times 10^{-11}m^3Kg^{-1}s^{-2}[/tex]
Please Hurry!!
Answer File Below!
Energy transformations that occur when a ball is thrown in the air
What is the mass of a sample of aluminum that absorbs 596 J of heat when the temperature is raised from 30.0°C to 100.1°C? Specific heat of aluminum = 0.900 J/g oC
Answer is: the mass of a sample of aluminum is 9.45 grams.
ΔT = 100.1°C - 30.0°C.
ΔT = 70.1°C.; change in temperature of a sample of aluminium.
Cp(Al) = 0.900 J/g·°C; specific heat capacity for aluminium.
Q = 596 J; heat absorbed.
Q = m(Al) · ΔT · Cp(Al).
m(Al) = Q ÷ (ΔT · Cp(Al)).
m(Al) = 596 J ÷ (70.1°C · 0.900 J/g·°C).
m(Al) = 9.45 g; mass of aluminium sample.
What element is most likely to form a diatomic molecule?
A.
Cr
B.
K
C.
Br
D.
Ga