Solder is a silver metal used to hold pipes together. When the solder is heated, it melts and acts as a type of metal "glue." Mrs. Hanley heats a piece of solder until it melts between two pipes. What best identifies the point at which a physical change first takes place?
A)when the solder melts
B)when the solder cools down
C)when the solder is a soft metal
D)when the solder becomes solid again
Answer:
A
Explanation:
Reactants are on the left side of the equatio. Arrow true or false
In an ionic bond, how does a sulfur atom achieve an octet of electrons?
By gaining 2 electrons
By gaining 6 electrons
By losing 2 electrons
By losing 6 electrons
rain gauge non examples
Answer:
Explanation:
?? sorry but i do not get what u said
The pH of a solution is 3.81. What is the OH concentration in the solution?
Answer:
6.46 × 10⁻¹¹ M
Explanation:
Step 1: Given data
pH of the solution: 3.81
Step 2: Calculate the pOH of the solution
We will use the following expression.
pH + pOH = 14.00
pOH = 14.00 - pH = 14.00 - 3.81 = 10.19
Step 3: Calculate the concentration of OH⁻ ions
We will use the definition of pOH.
pOH = -log [OH⁻]
[OH⁻] = antilog -pOH = antilog -10.19 = 6.46 × 10⁻¹¹ M
What can scientists learn by studying fossils? I HAVE ANSWER
It is all of them.
how the Earth's climate has changed over time
how species have changed over time
the appearance of an organism and its structures
how the Earth's surface has changed over time
Answer:
dweyflgyegfuyegfyegrygeyrgyr8ogeyurkgevyrujfryujftewy
Explanation:
jk b or e
What is the mass of 1.58 moles of CH4
25.4 g CH₄
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Atomic Structure
Reading a Periodic TableStoichiometry
Using Dimensional AnalysisExplanation:Step 1: Define
1.58 mol CH₄
Step 2: Identify Conversions
[PT] Molar Mass of C - 12.01 g/mol
[PT] Molar Mass of H - 1.01 g/mol
Molar Mass of CH₄ - 12.01 + 4(1.01) = 16.05 g/mol
Step 3: Convert
Set up: [tex]\displaystyle 1.58 \ mol \ CH_4(\frac{16.05 \ g \ CH_4}{1 \ mol \ CH_4})[/tex]Multiply/Divide: [tex]\displaystyle 25.359 \ g \ CH_4[/tex]Step 4: Check
Follow sig fig rules and round. We are given 3 sig figs.
25.359 g CH₄ ≈ 25.4 g CH₄
An ore sample is found to contain 10.500000 g of cobalt and 87.3 g waste rock (gangue). What is the
percent by mass of cobalt in the ore?
Answer:
[tex]\% Co=10.7\%[/tex]
Explanation:
Hello!
In this case, since this is a mixture composed by cobalt and waste rock, we can compute the percent by mass of cobalt as shown below:
[tex]\% Co=\frac{m_{Co}}{m_{Co}+m_{waste}} *100\%\\\\[/tex]
Thus, we plug in to obtain:
[tex]\% Co=\frac{10.500000g}{10.500000g+87.3} *100\%\\\\\% Co=10.7\%[/tex]
Best regards!
HELP IM AB TO CRY
What is the force of gravity (in Newtons) acting between the Earth and a 125-kg person standing on the surface of the Earth?
Answer:
1.23 × 10³ N
Explanation:
Step 1: Given and required data
Mass of the person (m): 125 kgAcceleration due to the gravitational force (g): 9.81 m/s²Step 2: Calculate the force acting between the Earth and a 125-kg person standing on the surface of the Earth
We will use Newton's second law of motion.
F = m × g
F = 125 kg × 9.81 m/s²
F = 1.23 × 10³ N
What happens as elevation increases?
Answer:
As altitude increases, the amount of gas molecules in the air decreases the air becomes less dense than air nearer to sea level.
Explanation:
If the initial temperature of a movable cylinder was 130 degrees Celsius
with a pressure of 1 ATM and an initial volume of 2 Liters, what would
the new volume be if the temperature was lowered to 324 degrees Kelvin
and the pressure was raised to 1.1 ATM?
Answer: The new volume will be 1.5 L
Explanation:
The combined gas equation is,
[tex]\frac{P_1V_1}{T_1}=\frac{P_2V_2}{T_2}[/tex]
where,
[tex]P_1[/tex] = initial pressure of gas = 1 atm
[tex]P_2[/tex] = final pressure of gas = 1.1 atm
[tex]V_1[/tex] = initial volume of gas = 2 L
[tex]V_2[/tex] = final volume of gas = ?
[tex]T_1[/tex] = initial temperature of gas = [tex]130^0C=(130+273)K=403K[/tex]
[tex]T_2[/tex] = final temperature of gas = [tex]324K[/tex]
Now put all the given values in the above equation, we get:
[tex]\frac{1\times 2}{403}=\frac{1.1\times V_2}{324}[/tex]
[tex]V_2=1.5L[/tex]
The new volume will be 1.5 L
106Pd2+
How many protons, electrons, and neutrons are in this?
Answer:
Protons = atomic #
Neutrons = Mass # - atomic #
Electrons = atomic # - charge ( If no charge electrons = 0 therefore electrons = atomic # only if No charge not including the ^ number thing)
The element is Palladium
atomic number = 46.
Atomic Mass = 106
Therefore The answer being
Protons = 106
Neutrons = 60
Electrons = 104
( Sorry im only in the 9th grade but i did the best i could) The reason electrons are 104 is because of the 2+ meaning 2+ more protons than electons.
Which is the weakest acid?
1. Butane
2. But-1-yne
3. Water
4. But-1-ene
n a volumetric analysis experiment, a solution of sodium oxalate (Na 2C 2O 4) in acidic solution is titrated with a solution of potassium permanganate (KMnO 4) according to the following balanced chemical equation: 2KMnO4(aq) + 8H2SO4(aq) + 5Na2C2O4(aq) → 2MnSO4(aq) + 8H2O(l) + 10CO2(g) + 5Na2SO4(aq) + K2SO4(aq) It required 40.0 mL of 0.0335 M KMnO4 to reach the endpoint. What mass of Na2C2O4 was present initially?
Answer:
mNa₂C₂O₄ = 0.4489 g
Explanation:
This is a problem of stechiometry. in this case, we need to find the mole ratio between the permanganate solution and the oxalate. This can be seen in the balanced reaction which is the following:
2KMnO₄ + 8H₂SO₄ + 5Na₂C₂O₄---> 2MnSO₄ + 8H₂O + 10CO₂ + 5Na₂SO₄ + K₂SO₄
According to this balanced reaction, we have a mole ratio of 2:5 between permanganate and oxalate, so, the first thing to do here is calculate the moles of the permanganate needed to reach the endpoint of this titration:
n = M * V
Replacing we have:
nKMnO₄ = 0.0335 mol/L * 0.040 L = 0.00134 moles
With these moles, and the above mole ratio, we can determine the moles of the oxalate:
2 moles KMnO₄ -------> 5 moles Na₂C₂O₄
0.00134 moles ---------> X
X = 0.00134 * 5 / 2
nNa₂C₂O₄ = 0.00335 moles
Finally, with the molecular mass of Na₂C₂O₄, we can determine the mass of the oxalate:
Molecular weights:
Na: 23 g/mol; C: 12 g/mol; O: 16 g/mol
MMNa₂C₂O₄ = (23*2) + (2*12) + (4*16) = 134 g/mol
mNa₂C₂O₄ = nNa₂C₂O₄ * MM
mNa₂C₂O₄ = 0.00335 * 134
mNa₂C₂O₄ = 0.4489 gHope this helps
Find the moles in 0.0023 of Co, at STP:
i have understood that the meaning of life is
I have understood that the meaning of life is to have a vision and live a purposeful life.
Living a meaningful life is concerned about the essence of waking up everyday and having something meaningful that you're doing or engaging yourself into what you have vision about.
Life is good and lively when you have a vision, this vision is drive by a passion for a particular thing. When you're visionary, you will be happy every day and it is visionaries that change the world positively.
Over an extended period of time, this vision will be brought into life where people can benefit from it. Here, is where purpose comes in.
When you're able to impact positively into another people's life and make their life easier, you're living a purposeful life.
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An experiment shows that a 250 −mL gas sample has a mass of 0.436 g at a pressure of 742 mmHg and a temperature of 27 ∘C.
What is the molar mass of the gas?
Answer:
41.9 g/ mol hope that helps you out
Explanation:
d=p.m/ r.t
How does a limiting reagent affect how much product is formed?
O A. The amount of product will be limited by the molar mass of the
limiting reagent
B. The amount of product will be limited by the sum of the reactant
coefficients.
C. The amount of product will be limited by the number of moles of
the limiting reagent.
D. The amount of product will be limited by leftover amounts of other
reactants.
Answer:
C. The amount of product will be limited by the number of moles of
the limiting reagent.
Explanation:
a p e x :)) i just took the quiz
The amount of product will be limited by the number of moles of
the limiting reagent. Hence, option C is correct.
What is a Limiting reagent?The reactant that gets consumed early in the reaction restricts the quantity of product which will be produced in the chemical reaction. Thus, the reactant that gets consumed early in a chemical reaction is a limiting reagent.
Hence, the amount of product will be limited by the number of moles of the limiting reagent.
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Suppose a student repeats a measurement two times and then calculates the standard deviation. Because the standard deviation is small, the student reports that their experiment was extremely precise. Is the student's conclusion appropriate?
A) No, because there were not enough measurements to use standard deviation.
B) Yes, because a small standard deviation indicates greater precision
C) Yes, because a small data set always has excellent precision
D) No, because a large standard deviation indicates greater precision
Answer:b
Explanation:
How many atoms of which elements are represented by the following formula?
H3PO4
Writing Prompt/Open-Ended Question
What are limiting reactants? How can you predict how much of a product you will create if you know how much of a reactant you used?
Answer:
If you are given a chemical equation and specific amounts for each reactant in grams, you have to follow these steps, in order, to determine how much product can possilby be made:
1. Convert each reactant into moles of the product.
2. Determine which reactant is the limiting reactant.
3. Convert the moles of product, from the limiting reactant, to grams.
Explanation:
what is the highest energy level of an atom with 37 electrons
Answer:
rubidium is your answer for this question
An atom of carbon contains 6 total electrons. How many of these electrons are in s orbitals?
1
2
4
6
Answer:
4
Explanation:
total electrons = 6
electronic configuration = 1s^2, 2s^2, 2p^6
so in s orbital there are 4 electrons.
Hope it helps you (｡◕‿◕｡)
Ionic compounds form because ___ charges attract
Answer:
Ionic bonding is the attraction between positively- and negatively-charged ions. These oppositely charged ions attract each other to form ionic networks (or lattices). Electrostatics explains why this happens: opposite charges attract and like charges repel.
Explanation:
Ionic compounds form because opposite charges attract.
In an ionic compound, positive and negative ions come together to form a stable structure. This occurs when an atom loses electrons to become a positively charged ion (cation) and another atom gains those electrons to become a negatively charged ion (anion). The positive and negative charges of the ions attract each other, resulting in the formation of an ionic bond.
This attraction between positive and negative charges is what holds ionic compounds together. The strong electrostatic forces of attraction between ions result in a lattice structure, where each ion is surrounded by oppositely charged ions.
Thus, ionic compounds are formed because opposite charges attract.
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Please explain how to do this one !! Which of the following ionic solids would have the largest lattice energy?
CaBr2
NaF
CsI
SrO
BaSO4
Answer:
I think it's Csl
I don't really know
but follow me and heart this
Does anyone know the answers for these
Answer: 1. 0.045moles
2. 2.10 grams
Explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.
To calculate the moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}[/tex]
1. [tex]\text{Number of moles of zinc nitrate}=\frac{8.51g}{189.36g/mol}=0.045moles[/tex]
2. Mass of [tex]C_2H_4=moles\times {\text {Molar mass}}=0.075moles\times 28.05g/mol=2.10g[/tex]
How many chromosomes should be in each cell labeled with an X? A. 32 B. 16 C. 8 D. 4
Answer:
B.16 B.16 B.16
Explanation:
B.16 B.16 B.16 B.16 B.16when energy transforms, which of the following does it produce?
A. heat
B. light
C. sound
D. motion
motion
Explanation:
it works in our daily life
What is the definition of energy (in scientific terms)?
A. The motion of an object
B. The ability to do work
C. A force used on an object
D. A change in temperature
What is berylium phosphide anion?
Answer:
Molecular Formula, Be3P2. Synonyms. Beryllium phosphide. Beryllium phosphide (BeP2). EINECS 261-137-1. 57620-29-8. 58127-61-0. Molecular Weight.
Molecular Formula: Be3P2
Molecular Weight: 88.98407 g/mol
Structure: Find Similar Structures
PubChem CID: 6453515
Explanation: