Did the addition of salt change a physical or chemical property of water?
Answer:
Chemical
Explanation: By dissolving it is no longer salt by itself so it is a chemical change
answer this pls thanks
Answer: It is element nitrogen. It has an atomic number of 7 and the valence electron is 5. It needs 3 electrons to complete its octet state. That's why sometimes it has the oxidation number of -3 in ammonia.
PLS HELP
True or False: Water molecules, as a liquid, are very spread apart because of their attractions for one another. *
whats the formula for mass
Answer:
The unit of molar mass is kg/mol. Where, m = mass, v = velocity.
Hope that helps :)
Does the model correctly represent the electron dot diagram of magnesium? Why or why not? Check all that apply.
M g with 1 dot above and 1 right.
*{Yes, because the chemical symbol of magnesium is Mg.}
No, because the chemical symbol of magnesium is Mn.
*{Yes, because magnesium has two valence electrons.}
No, because magnesium has seven valence electrons.
No, because both of the dots should be on top of the chemical symbol
Answer 1 and 3
Answer:
1 and 3
Explanation:
Answer: A and B or 1 and 3
Explanation:
Who knows the answer to this please help
Someone answer these please! It’s multiple choice
Answer: Number 1 is titanium.
The one where you calculate a tin block is 13.0cm.
3. Is A) Same Density And Same Chemical Properties.
4. Is also A. Ne
Explanation:
What makes the element oxygen different from the element hydrogen?
Answer: the difference is due to the fact that one water molecule has two hydrogen atoms to one oxygen this means it takes two water molecules (2 H2O) to make one oxygen molecule (02) .At the same time however two molecules of water (2 H20) can make two molecules of hydrogen (2 H20)
Explanation: hope this helped and mark me as brainliest please =)
Which of these describes a challenge that the engineer of a high-altitude
airplane would need to consider?
A. More fuel is used at higher altitudes.
B. The airplane may succumb to the power of gravity as lift
decreases at higher altitudes.
C. The airplane may need a heat shield for protection from sonic
booms.
O D. The airplane will create more drag at higher altitudes than lower
altitudes.
Answer:
I think its (B)
Explanation:
as when the air thins out at higher elevations, your lift decreases so at some point, the plane cant produce enough lift to overcome gravity.
what phenomenon occurs after mass extinction?
Answer:
Diversification and adaptive radiation.
Explanation:
This is to all the people who keep asking dating questions on brainly
It's not tender
Answer:
AGREE
Explanation:
thanks for the free points also :)
As water is cooled, its density increases until it reaches about
A. 4°C
B. 25°C
C. O'C
D. -2°C
If the temperature of a substance increases will the particles of that substance be moving faster or slower or at the same speed as they were before the temperature changed
Answer:
If the temperature increases, temperature reflects the speed of the molecules, so if the molecules are at a higher temperature, they are faster and they start to break bonds and new things react.
Explanation:
If this same quantity of energy were transferred to 2.5 kg of water at it's boiling point what fraction of the water would be vaporized
Answer:
Fraction of water that can be vaporized = 0.0961 or 9.61%
Note : The question is incomplete. The complete question is given below:
A serving of Cheez-Its releases 130 kcal (1 kcal = 4.18 kJ) when digested by your body.
If this same quantity of energy were transferred to 2.5 kg of water at its boiling point, what fraction of the water would be vaporized?
Explanation:
Energy released by a serving of Cheeze-Its = 130 kcal
Since 1 kcal = 4.18 kJ, 130 kcal = 130 * 4.18 kJ = 543.4 kJ
Heat of vaporization (evaporating or condensing) Hv, of water = 2260 J/g
From formula, quantity of heat, Q = mass * heat of vaporization
mass of water = 2.5 kg = 2500 g
Q = 2500 g * 2260 J/g
Q = 5650000 J = 5650 kJ
Therefore 2.5 kg of water requires 5650 kJ of heat for complete vaporization
Fraction of water that can be vaporized by 543.4 kJ energy = 543.4/5650
Fraction of water that can be vaporized = 0.0961 or 9.61%
The density of copper is 8.9 g/mL. What is the volume of 20.5 g copper?
Answer:
density = 8.9 g/ml
m = 20.5 g
V = ... ?
density = m/V
V = m / density
= 20.5 / 8.9
= 2.30337 ml
A student needs to determine the density of an unknown rock sample by dropping the rock into a graduated cylinder containing water. The original volume in the graduated cylinder is 23.0 ml. The student then drops the rock sample into the graduated cylinder and determines the new volume to be 30.0 ml. If
the mass of the rock is determined to be 20.4 grams, what is the density of this sample?
Answer:
The answer is 2.91 g/mLExplanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\ [/tex]
volume = final volume of water - initial volume of water
volume = 30 - 23 = 7 mL
We have
[tex]density = \frac{20.4}{7} \\ = 2.9142857...[/tex]
We have the final answer as
2.91 g/mLHope this helps you
An object has a mass of 441 g and a volume
of 10 cm3. What is the density of the object
in g/cm3?
The density is the ratio of the mass to the volume. The density of the object is 44.1 g/cm³.
What is density?Density (ρ) is the quantitative measurement of the substance having grams of mass that are dissolved per cubic meter of the solution. The density is calculated as:
ρ = M ÷ V
Given,
Mass of the object = 441 gm
The volume of the object = 10 cubic meter
Density is calculated as:
ρ = 441 ÷ 10
= 44.1 g/cm³
Therefore, 44.1 g/cm³ is the density of the object.
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Question 19 of 25
Which sentence best explains the observed trend in atomic radius as you
move down the periodic table?
A. The more neutrons a nucleus has the larger the atomic radius.
B. The more energy levels that are occupied by electrons, the larger
the atomic radius.
C. The more core electrons an atom has, the smaller the atomic
radius.
D. The more paired electrons there are, the smaller the atomic radius.
SUBMI
Answer:
sentence B.
Explanation:
The number of energy levels increases as you move down a group as the number of electrons increases. Each subsequent energy level is further from the nucleus than the last. Therefore, the atomic radius increases as the group and energy levels increase.
Answer: B
Explanation: I just took it trust me and keep up the work
What does the symbol △ in a chemical equation mean?
Answer:
Delta, or subject to change.
Explanation:
Δ→ triangle indicates that the reaction is being heated.
What is a chemical equation?Chemical equations are symbolic representations of chemical reactions in which the reactants and the products are expressed in terms of their respective chemical formulae.
To express heating, we usually use Δ over reaction arrows like:
[tex]CaCO_ 3[/tex]. Δ → [tex]CaO+O_2.[/tex]
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Use the equation below to solve the problem that follows.
2H2 (g) + O2 (g) → 2H2O (g)
When David reacts 13.8 grams of hydrogen gas with excess oxygen, 87.0 grams of water are formed. Calculate his percent yield of water.
Im very loss with this question
Percent yield of water : 70%
Further explanationReaction
2H₂ (g) + O₂ (g) → 2H₂O (g)
mol H₂(MW= 2 g/mol) :
[tex]\tt \dfrac{13.8~g}{2~g/mol}=6.9~mol[/tex]
mol H₂O = mol H₂ = 6.9
mass H₂O(theoretical) :
[tex]\tt 6.9\times 18~g/mol=124.2~g[/tex]
[tex]\tt \%yield=\dfrac{actual}{theoretical}\times 100\%\\\\\%yield=\dfrac{87}{124.2}\times 100\%=70\%[/tex]
Why can gases be compressed easier than liquids and solids?
F.
Gases have smaller atomic nuclei than solids and liquids.
G.
Solid materials go through chemical changes when they are compressed.
H.
The electron clouds in atoms of solids and liquids are much larger.
J. The space between gas molecules is bigger than solid and liquid molecules.
Answer:
J
Explanation:
Can somebody help me with this??!
If 175 grams of lead (ll) iodide is produced from the reaction, how many moles of potassium nitrate are produced?
Equation: 2KI + Pb(NO₃)₂ = 2KNO₃ + Pbl₂
Moles of potassium nitrate produced : 0.76
Further explanationThe reaction equation is the chemical formula of reagents and product substances
A reaction coefficient is a number in the chemical formula of a substance involved in the reaction equation. The reaction coefficient is useful for equalizing reagents and products.
Reaction
2KI + Pb(NO₃)₂ ⇒ 2KNO₃ + Pbl₂
MW KNO₃ : 101.1032 g/mol
MW Pbl₂ = 461,01 g/mol
175 grams of Pbl₂ , mol :
[tex]\tt mol=\dfrac{175}{461.01}=0.38[/tex]
mol ratio KNO₃ : Pbl₂ = 2 : 1, so mol KNO₃ = 0.38 x 2 = 0.76
Mass of KNO₃ :
[tex]\tt mass=0.76\times 101.1032=76.838~g[/tex]
Carbon dioxide is formed by the given formula.
C(s)+O2(g)→CO2(g)
Carbon dioxide is
A
a compound of two elements, carbon and oxygen.
B
a mixture of two compounds, carbon and oxygen.
C
a compound of two atoms, carbon and oxygen.
D
an element of two atoms, carbon and oxygen.
Answer:
A
Explanation:
Which indicates how evidence of climate change supports the theory of continental drift?
coal fields in several continents
volcano formation
glacial evidence found in South America
folded mountains in Africa and South America
Glacial evidence found in South America, do indicate how evidence of climate change has supports the theory of continental drift.
Climate change occurs daily all over the world. This is largely due to man's activities that has affected the atmosphere and the earth.Continental drift is simply known as the theory that states that the continents at a time has formed a single landmass, broke up, and drifted to their present locations. Glacial evidence in South America has made man to believe more in the continental drift hypothesis.Conclusively, we can therefore say that Glacial evidence found in South America, do indicate how evidence of climate change has supports the theory of continental drift.
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Answer:
glacial evidence found in South America
Explanation:
Which of the following describes the energy transformations that occur when a toaster is used to make toast?
Thermal energy is transformed into chemical energy in the toaster, and chemical energy is transformed into thermal energy in the toast.
Electrical energy is transformed into thermal energy in the toaster, and chemical energy is transformed into thermal energy in the toast.
Light energy is transformed into thermal energy in the toaster, and thermal energy is transformed into chemical energy in the toast.
Electrical energy is transformed into thermal energy in the toaster, and thermal energy is transformed into chemical energy in the toast.
Answer:
Thermal energy (B)
Explanation:
just did it
Electrical energy is transformed into thermal energy in the toaster, and chemical energy is transformed into thermal energy in the toast. Hence option b is correct.
What is chemical energy?Chemical energy is defined as chemical substances' potential energy, which is released as they experience chemical reactions and change into other substances. Additionally, it is what binds a substance's molecule's together. The body transforms or changes the chemical energy in food into heat and mechanical motion.
The wire attached to the power source transmits electrical energy to the toaster. The heating element is a part of the toaster. This heating element transforms electrical energy into heat energy, which aids in toast preparation, when it comes into contact with it. Thus, with an electric toaster, electrical energy is converted to heat energy.
Thus, electrical energy is transformed into thermal energy in the toaster, and chemical energy is transformed into thermal energy in the toast. Hence option b is correct.
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8
Calcium carbonate (limestone) decomposes when heated.
Caco, + CaO + CO2
b) Calculate the volume of carbon dioxide produced if 10 grames were decomposed.
Explanation:
Equation -
CaCO₃ → CaO + CO₂
molecular masses of -
CaCO₃ = 40+12+16×3 = 100 g/mol
CaO = 40+16 = 56 g/mol
CO₂ = 12+16×2 = 44 g/mol
Now,
If 100 g of CaCO₃ is decomposed then it produces 56 g of CaO and 44g of CO₂
Then,
If 1 g of CaCO₃ is decomposed then it produces 56/100g of CaO and 44/100g of CO₂
Now,
Here in question, 10g of CaCO₃ is decomposed
It means, It produces
56/100 × 10 = 56/10 = 5.6 g of CaO and
44/100 × 10 = 44/10 = 4.4 g of CO₂
Now,
we get that 10 g of CaCO₃ on burning produces 4.4 g of CO₂
we need to calculate volume of 4.4 g of CO₂
mole = mass/Gram molecular massThen,
mole = 4.4/44 = 0.1
Now,
volume = mole × 22.4 (in Litres)
= 0.1 × 22.4 = 2.24 L
Hence,
2.24 L of CO₂ will be produced when 10g of CaCO₃ decomposed.
A gas sample in a rigid container at 455 k is cooled to 273 k where it has a pressure of 1 atm. What was the original pressure of the gas in mmHg
Answer:
1270 mmHg
Explanation:
Answer : 1270 mmhg
Explanation:
How many Mg atoms are found in 1.00 mole of MgO?
Answer:
From the equation above we get 1 amu = 1g/NA or 1 amu = 1.66054x10^-24 g. Thus, a mole of magnesium atoms has a mass of NA x 24.305 amu x (1.66054x10^-24 g/amu) = 24.305 g. A mole of magnesium atoms has a mass of 24.305 g.
Explanation:
1 mole of MgO has 146.35 × [tex]\rm 10^2^3[/tex] atoms of Mg.
The number of atoms found in a mole of compound has been given by relationship between the mole and the Avogadro number. The Avogadro number has been the constant that has been given by the number 6.023 × [tex]\rm 10^2^3[/tex].
The relationship between the atoms and mole has been given by:
1 mole = 6.023 × [tex]\rm 10^2^3[/tex] atoms.
So, the number of atoms that has been present in1 mole of the MgO has been equivalent to the Avogadro number.
Thus, 1 mole of MgO has 6.023 × [tex]\rm 10^2^3[/tex] atoms.
The mass of there has been 1 molecule of Mg in the MgO compound, thus, the atoms of Mg can be given by:
Mg atoms = Mass of Mg × Avogadro number
Mg atoms = 24.3g × 6.023 × [tex]\rm 10^2^3[/tex]
Mg atoms = 146.35 × [tex]\rm 10^2^3[/tex]
Thus, 1 mole of MgO has 146.35 × [tex]\rm 10^2^3[/tex] atoms of Mg.
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PLEASE HELP
The Octet Rule explains why
A. Atoms form chemical bonds to create compounds
B. The electronegativity of fluorine is higher than chlorine
C. Ionic compounds have high boiling and melting points
D. Valence electrons are used in chemical bonding
E. Valence electrons are used in chemical bonding
It's not D that's all I know. Please answer with an explanation if you know.
Answer:
Explanation:
E