Answer:
D. How frequently do earthquakes occur in San Francisco?
- How much power does it take to lift a
1,000 N load 10 m in 20 s?
Answer:
"500 Joule/sec" is the right answer.
Explanation:
The given values are:
Force,
F = 1000 N
Velocity,
s = 10 m
Time,
t = 20 s
Now,
The power will be:
= [tex]\frac{Force\times Velocity}{Time}[/tex]
On putting the values, we get
= [tex]\frac{1000\times 10}{20}[/tex]
= [tex]\frac{10000}{20}[/tex]
= [tex]500 \ Joule/sec[/tex]
When iron combines with oxygen in a moist environment, rust forms because of a
A.
change in density.
B.
chemical reaction.
C.
change in temperature.
D.
physical reaction.
Students performed an investigation on how aluminum cans taken to a recycle center were able to be reused. They found out an aluminum can undergoes which type of change?
A.
a physical change because the material remains the same
B.
a chemical change because new metal is formed
C.
a physical change because the can is heated
D.
a chemical change because an old can is changed into a new can
Which of the following is an example of a compound?
A.
carbon
B.
copper
C.
water
D.
iron
A student placed a small chip of limestone into a hydrochloric acid solution, and carbon dioxide gas was released. The carbon dioxide provided evidence that
A.
only a loss of mass occurred.
B.
only a physical change occurred.
C.
the formation of an element occurred.
D.
a chemical change occurred.
As part of a study, a scientist observed a number of different molecular changes in matter. Which of the following observations provides evidence of a physical change?
A.
a cake that was baked from many ingredients
B.
using heat to burn a log in a fireplace
C.
using light to produce sugar in plants
D.
a bottle that was broken into many small pieces
What is formed when a sodium atom and chlorine atom react chemically?
A.
an electron
B.
a neutron
C.
a compound
D.
an element
Which substance is composed of only one type of atom?
A.
salt
B.
water
C.
gold
D.
sugar
A mixture that has the same composition throughout is what kind of mixture?
A.
Taco Salad
B.
Heterogeneous
C.
Sharknado
D.
Homogeneous
John and Lisa collected a sample of ocean water and placed it in a jar. Within a couple of days, the water had evaporated and salt was visible at the bottom of the jar. This is an example of a
A.
solute being dissolved.
B.
chemical change.
C.
new substance being formed.
D.
physical change.
Which term correctly describes all of the following materials?
salt water, vinegar, bronze, air, beach sand
A.
solutions
B.
mixtures
C.
compounds
D.
elements
In which classification of matter are the components chemically combined?
A.
alloy
B.
compound
C.
mixture
D.
colloid
Since sodium chloride is classified as a compound, a sample of it contains
A.
matter that cannot be reduced to atoms.
B.
atoms that are gases, liquids, and solids.
C.
a solution of atoms and molecules.
D.
more than one kind of atom.
Which is the best example of a chemical change?
A.
paper tearing
B.
butter melting
C.
egg cooking
D.
water evaporating
Which is a physical change?
A.
rust forming on an iron fence
B.
a copper roof changing color
C.
a sheet of paper shredding
D.
a piece of wood burning
What is needed to change ice into water?
A.
stirring
B.
energy
C.
chemicals
D.
air
A group of students observed the formation of bubbles when water boiled. What happened to matter because of the physical change to the water?
A.
Matter was conserved when it changed form.
B.
New matter was created in the bubbles.
C.
Old matter was destroyed as the water turned to gas.
D.
The composition of the matter changed.
Which of the following results when hydrogen and chlorine chemically bond to form hydrogen chloride?
A.
a compound
B.
a solution
C.
a precipitate
D.
a mixture
What is the smallest unit of an element that still retains the element’s properties?
A.
an atom
B.
a crystal
C.
a molecule
D.
a proton
Which type of matter can be separated by physical means?
A.
compound
B.
element
C.
mixture
D.
atom
Which state has a definite shape and volume?
A.
Sharknado 2: The Second One
B.
Gas
C.
Solid
D.
Liquid
Answer:
A. change in density.
Calculate the mass of Iron in 40g of Fe203
Answer:
Explanation:
¿Cómo se llama el grupo IIA de la tabla periódica?
Answer:
los metales alcalinotérreos: berilio (Be), magnesio (Mg), calcio (Ca), estroncio (Sr), bario (Ba) y radio (Ra).
o simplemente llamado grupo 2A
Explanation:
Which form of emission is commonly not written in nuclear equations because they do not affect charges, atomic numbers, or mass numbers?
alpha particle
beta particle
gamma ray
Answer: It is Gamma ray
Answer:
C. gamma ray
(Photo for proof at the bottom.)
Explanation:
A gamma ray is a type of radiation that occurs when an unstable nucleus emits a photon, the smallest unit of light. A photon has no mass or charge. Atomic and mass numbers are written based on the mass of the atom. But since no mass is lost when a photon is emitted, writing the emission of it isn't necessary.
Here's a photo of Edge, good luck.
Hi can someone who know the answers tell me what it is and pls don't send me a link also don't send me the wrong answers if you don't know it's ok :)
Answer:
you diba ikaw ang nagpamalimali diba no
Glycerol has a molar mass of 92.09g/mol. Its percent composition is: 39.12% C, 8.75% H,
and 51.12% O. What is the molecular formula for glycerol?
Answer:
Molecular formula => C₃H₈O₃
Explanation:
From the question given above, the following data were obtained:
Carbon (C) = 39.12%
Hydrogen (H) = 8.75%
Oxygen (O) = 51.12%
Molar mass of compound = 92.09 g/mol
Molecular formula =?
Next, we shall determine the empirical formula of the compound. This can be obtained as follow:
C = 39.12%
H = 8.75%
O = 51.12%
Divide by their molar mass
C = 39.12 / 12 = 3.26
H = 8.75 / 1 = 8.75
O = 51.12 / 16 = 3.195
Divide by the smallest
C = 3.26 / 3.195 = 1
H = 8.75 / 3.195 = 2.7
O = 3.195 / 3.195 = 1
Thus, the empirical formula is CH₂.₇O
Finally, we shall determine the molecular formula of the compound. This can be obtained as follow:
Empirical formula = CH₂.₇O
Molar mass of compound = 92.09 g/mol
Molecular formula =?
Molecular formula = Empirical formula × n
Molecular formula = [CH₂.₇O]ₙ
92.09 = [12 + (2.7×1) + 16] × n
92.09 = 30.7n
Divide both side by 30.7
n = 92.09 / 30.7
n = 3
Molecular formula = [CH₂.₇O]ₙ
Molecular formula = [CH₂.₇O]₃
Molecular formula = C₃H₈O₃
what is the mass of 0.200 mol of calcium
HELP ASAP!! 12pts!
What is the molarity of an aqueous solution containing 7.5 moles of
calcium chloride in 12.75 L of solution?
A. 0.59 M
B. 1.7M
C. 7.5M
D. 95.6 M
Answer:
The correct answer is 0.59M
How
many
molecules are in 8.55x10-15 moles of a substance
Answer:
Know this
1mole of a substance contains 6.022x10²³molecules
Now
8.55x10^-15moles x 6.022x10²³molecules/1mole
=5.15x10^9molecules.
What would be the volume, in liters measured at STP, of 9.75 moles of carbon monoxide?
I
Alex built a model to show how light bends when placed into water. To do this, Alex filled a fish tank up with water, and shined a green laser through the water. The angle he shined the laser into the fish tank is the line above the water, and the angle that the light bent is seen below the water. What is a limitation of this model? The model cannot show how light bends. The model is unable to use different colors of light The model cannot calculate the speed of light The model is not 3 dimensional
Answer:
The model cannot show how light bends.
Explanation:
How would you find the density of a can of soda pop?
A. Find the mass of the can of soda pop and then multiply by the number of cubic centimeters in the can
B. Find the mass of the can of soda pop and then divide by the number of cubic centimeters in the can
C. Convert a gallon into cubic centimeters and then divide by the mass of the can of soda pop
D. Convert a gallon into cubic centimeters and then subtract the mass of the can of soda pop
Answer:
it's A.
Explanation:
have uh good day ma :)))))))
moles of H2O are needed to exactly react with 2.0 moles of Ca
Answer:
4
Explanation:
so first write the balance equation
Ca+2H2O---->Ca(OH)2 + H2
then use molar ratio of H2O and Ca
which is 2:1 so if there are 2 moles of ca there will be 4 moles as you times it by 2. like this
Ca:H2O
1:2
2:4
Hope this helps u understand:)
NO LINKS OR FILES
Using Ohm's Law and Watt's Law. write the formula to find each measurement
Wattage (Watts)
Resistance (Ohms)
Voltage (Volts)
and/or
Current (Amps)
and/or
Explanation:
Mathematically, Ohm's law is given by :
V = IR
Where
V is voltage
I is current
R is resistance
The electric power of an electrical appliance is given by:
P = VI
Wattage = VI
Resistance, [tex]R=\dfrac{V}{I}[/tex]
Current, [tex]I=\dfrac{V}{R}[/tex]
Hence, this is the required solution.
Please help me out!!!
Larissa is making sautéed purple cabbage. First, she washes and cuts the cabbage into long thin strands. Then, she puts a pan on the stove and adds butter. She allows the butter to melt and turn to liquid. Next, she adds the cabbage to the butter, sprinkles some salt on it, and stirs it. Larissa watches as the cabbage sizzles, releases steam, and softens. To finish the side dish, she adds a squeeze of lemon juice to it, which causes it to change from purple to pink. Finally, Larissa empties the cabbage into a bowl and puts it on the dinner table.
Which of the events involves a chemical reaction?
Larissa washes and cuts some purple cabbage into long thin strands.
Larissa adds the cabbage to the butter with a sprinkle of salt and stirs it.
Larissa adds butter to a pan and allows it to melt and turn to liquid.
Larissa adds a squeeze of lemon juice to the cabbage, and it turns pink.
Larissa empties the cabbage into a bowl and puts it on the dinner table.
Larissa watches as the cabbage sizzles, releases steam, and softens.
Answer:
what even is the question?
The total pressure of two unknown gases is 5 kPa. The partial pressure of one of the gases is 2.345 kPa, what is the partial pressure of the other gas?
Answer:
[tex]p_2=2.655kPa[/tex]
Explanation:
Hello there!
In this case, according to the Dalton's law, which states that the total pressure is equal the sum of the pressures of the gases in the mixture, we write the following for this system:
[tex]P_T=p_1+p_2[/tex]
Thus, we solve for the partial pressure of the gas #2 as shown below:
[tex]p_2=P_T-p_1\\\\p_2=5kPa-2.345kPa\\\\p_2=2.655kPa[/tex]
Best regards!
Consider the chemical equation. 2NBr3 + 3NaOH Right arrow. N2 + 3NaBr + 3HOBr If there are 40 mol of NBr3 and 48 mol of NaOH, what is the excess reactant?
Answer:
NBr₃ is the excess reactant.
Explanation:
2NBr₃ + 3NaOH → N₂ + 3NaBr + 3HOBrWe can solve this problem by calculating how many moles of NaOH would react completely with 40 moles of NBr₃, using the stoichiometric coefficients of the reaction:
40 mol NBr₃ * [tex]\frac{3molNaOH}{2molNBr_3}[/tex] =60 moles NaOHAs the required number of NaOH moles is higher than the available number (60 required vs 48 available), NaOH is the limiting reactant.
As such, the excess reactant is NBr₃.
Find the hydroxide concentration of a LiOH soultion that has a pOH of 8.65.
[OH] = _____ (round to 2 decimal places)
Answer: i need help
Explanation:
The mole fraction of helium in a saturated solution at 0°C is 1.2 x 10–6. Find the pressure of helium above the solution. Henry's law constant is 6.8 x 10–6 atm–1
Answer:
[tex]P=5.67atm[/tex]
Explanation:
Hello there!
In this case, since the Henry's law is shown below:
[tex]P=H/x[/tex]
Whereas x is the mole fraction, H the Henry's constant and P the pressure. In such a way, we plug in the aforementioned first two to obtain the corresponding pressure:
[tex]P=\frac{6.8 x 10^{-6} atm^{-1}}{1.2 x 10^{-6}} \\\\P=5.67atm[/tex]
Regards!
How does the composition of the nucleus change during fission, fusion, and radioactive decay?
The composition and mass of the nucleus changes during fission, fusion and nuclear decay process. During fission the nuclei breaks to light nuclei and in fusion the mass of nuclei formed is increased and in radioactive decay, the nuclear mass decreases.
What is nuclear fission?Nuclear fission is the process of breaking of a heavy nucleus into light nuclei with the release of energy. Hence, fission changes the identity of the atomic nuclei and form to light nucleus.
In nuclear fusion, two light nuclei fused up to form a heavy nucleus. Hence, the new composition changes the identity of the product. The number of protons, neutrons or electrons are differed in both fusion or fission.
Radioactive elements undergo nuclear decay by the emission of charged particles and it will reduce the atomic number or mass number or both based on the type of decay.
To find more on radioactive decay, refer here:
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Which solution will provide the LOWEST freezing point? Group of answer choices 1.2 M MgCl2 1.60 M KI 1.0 M Na2CO3 1.5 M NaCl
Answer:
KI 1.0 M
Explanation:
Freezing point of a substance is a colligative property. This means that it depends on the amount of substance present is the system.
The freezing point is given by; T - Ta = K * m * i
Where;
T = freezing point of the pure solution
Ta = freezing point of the solution containing the solute
K = freezing point constant
m = molality of the solution
i= Van't Hoff factor
If we look at all the options provided, KI has only two particles in solution and a molality of 1.0 m hence it should exhibit the lowest freezing point of solution.
How do gas particles respond to an increase in volume?
When the volume of a gas is increased, the gas particles respond by spreading out and occupying a larger space. This results in a decrease in the density of the gas and a decrease in the frequency of collisions between the gas particles.
How do gas particles respond to an increase in volume?As the gas particles spread out, the pressure exerted by the gas decreases.
This is because the pressure of a gas is directly proportional to the number of collisions per unit area of the container walls. When the volume increases, the same number of gas particles are distributed over a larger area, reducing the frequency of collisions and thus decreasing the pressure.
In summary, an increase in volume causes gas particles to spread out, resulting in a decrease in density and a decrease in pressure.
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What will the change in temperature be when 90 J are applied to 15 g of gold. (Cgold = 0.126 J/gºC)
Round your answer to the nearest whole number.
°C
E
3
4
5
Next
O
I 17
Answer:
48 °C
Explanation:
q = 90J
m = 15 g
C = 0.126 J/gºC
q = mct
90 = (15)(0.126)t
t = 47.62 °C = 48 °C
Answer:
Explanation:
Formula
E = m * c * Δt
Δt is what you seek.
Givens
E = 90 joules
m = 15 grams
c = 0.126
Solution
90 = 15 * 0.126 * Δt Divide by 15
90/15 = 15/15 * 0.126 * Δt
6 = 0.126 * Δt Divide by 0.126
6/0.126 = Δt
47.619 = Δt
Δt = 48 oC
3. 7moles of Ba(NO3)2 is dissolved in 75kg of distilled water.
What is the boiling point of this solution? Hint: Find molality first.
Answer:
100.14°C
Explanation:
The boling point elevation is a colligative property that describes the increasing in boiling point of a solution regard to the boiling point of the pure solvent. The equation is:
ΔT = Kf*m*i
Where ΔT is boiling point elevation
Kf is boiling point elevation (0.51°C/m for water)
m is molality of the solution (7moles Ba(NO3)2 / 75kg = 0.09333m
i is Van't Hoff factor = 3 for Ba(NO3)2 (Because its dissolution produce 3 ions = Ba²⁺ and 2 NO₃⁻
Replacing:
ΔT = 0.51°C/m*0.09333m*3
ΔT = 0.14°C is the boiling point elevation
As the boiling point of water is 100°C, the boiling point of the solution is:
100°C + 0.14°C =
100.14°C
1. If 80.0 ml of 3.00 M HCl is used to make a 100. ml of dilute acid, what is the molarity
of new dilute HCl solution?
We are given:
M1 = 3 Molar V1 = 80 mL
M2 = x Molar V2 = 100 mL
Finding the molarity:
We know that:
M₁V₁ = M₂V₂
where V can be in any units
(3)(80) = (x)(100)
x = 240/100 [dividing both sides by 100]
x = 2.4 Molar
Calcula cuantos mililitros de oxigeno se necesitan para quemar 3.5 ml de C₆H₆ a CNTP, la reacción sin balancear es la siguiente: C₆H₆ + O₂ → CO₂ + H₂O
Answer:
[tex]26.25mL \ O_2[/tex]
Explanation:
¡Hola!
En este caso, dado que se nos da reacción de combustión del benceno, primero debemos balancearla como se muestra a continuación:
C₆H₆ + ¹⁵/₂ O₂ → 6CO₂ + 3H₂O
Vemos que hay una relación molar entre el benceno y oxígeno de 1:¹⁵/₂, por lo que la relación de volúmenes es:
[tex]3.5 mL\ C_6H_6*\frac{15/2\ mL\ O_2}{1mL\ C_6H_6} \\\\=26.25mL \ O_2[/tex]
¡Saludos!
In steps 3 and 4 of the citric acid cycle, successive oxidations produce ________ as a waste product and the four-carbon carrier ________. In steps 3 and 4 of the citric acid cycle, successive oxidations produce ________ as a waste product and the four-carbon carrier ________. CO2; malate CO2; succinyl-SCoA ADP; oxaloacetate ADP; succinyl-SCoA CO2; oxaloacetate
Answer:
CO2; succinyl-SCoA
Explanation:
Citric acid cycle, also called Krebs cycle is the second stage of aerobic cellular respiration, which occurs in the mitochondrion. The kreb's cycle is made up of 7 distinct steps, with each involving series of enzymatic reactions.
According to this question, step 3 and 4 of the citric acid cycle involves an oxidation and decarboxylation reaction to produce 2 molecules of carbon dioxide (CO2) and a 4-carbon compound called succinyl group. A coenzyme A binds to the succinyl group to form succinyl-SCoA.
Potassium hydroxide is partially soluble as shown by the
following reaction:
KOH(s) K+ (aq) + OH(aq)
What is the poH of a 3.32 x 10-5 M KOH solution?
pOH =
Your answer should be rounded to three significant figures. Do not Include
units in your answer.
Answer: 4.48 or 4.47
Brakes are to a car as
to a nuclear-fission chain reaction.
A. fuel rods are
B. proliferation is
C. free neutrons are
D. control rods are
Answer:
D. control rods are
I hope dis helps :3
Brakers are to a car as control rods are to a nuclear-fission chain reaction. The correct option is D.
What is a nuclear-fission chain?A chain reaction occurs when neutrons generated during fission cause subsequent fission in at least one more nucleus.
This nucleus creates neutrons, and the cycle continues.
The process can be either controlled (nuclear power) or uncontrolled (nuclear weapons) (nuclear weapons).
Thus, the correct option is D. control rods are.
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