What is true about all real machines?
= equals
> greater than
work output may be < or > work input
work output > work input
work output < work input
work output = work input
Answer:It is always greater than the actual mechanical advantage because all machines must overcome friction. The mechanical advantage of a machine may be greater than, less than, or equal to 1, depending on the type of machine.
what element is not classified as a metal, nonmetal, or metalloid?
Answer:
Boron and/or Polonium
Explanation:
In the periodic table, you can see a stair-stepped line starting at Boron (B), atomic number 5, and going all the way down to Polonium (Po), atomic number 84. Except for Germanium (Ge) and Antimony (Sb), all the elements to the left of that line can be classified as metals.
3. Along which series is the bond angle increasing?
A. NH3 H2O CH4
B. CH4 NH3 H2O
C. H2O NH3 CH4
D. H2O CH4 NH3
The series along which the bond angle is increasing is: C. H2O NH3 CH4.
What is bond angle?Bond angle refers to the geometric angle that actually exists between angles that are adjacent to each other. It is also known to be the angle that is formed by three contiguous atoms.
We can see that as we move from H2O to NH3 then to CH4, the bond angle increases.
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How does the shape of a molecule affect the polarity of the molecule?
A. A molecule that is symmetrical in shape will have nonpolar bonds.
O B. A molecule that has a symmetrical shape will be a nonpolar
molecule.
C. A molecule with polar bonds will be polar, regardless of its shape.
D. A molecule that is not symmetrical will be a nonpolar molecule.
Answer:
It is A
Explanation:
If you think about it, no-polar covalent bonds are in a symmetrical line, and polar bonds are on the diagonals of the center atom.
I hope I helped :)
Answer:b
Explanation:
How many grams of water are produced when 2.50 mol oxygen reacts with hydrogen?
H2 + O2 + H2O
O A. 22.5 g
OB. 90.0 g
OC. 3.6 g
OD. 45.0 g
Answer:
Thus, when 2.5 mol of oxygen reacted with hydrogen, 2 * 2.5 mol = 5 so its A
A sample of hydrogen at 39°c exerts a pressure of 0. 163 atm. the gas is heated to 63 °c at
constant volume. what will its new pressure be?
answer in units of atm.
Answer:
[tex]p2 = 0.175atm[/tex]
5. A gas at 2.0 atm and 25 C has an initial volume of 1.00 L. The pressure of the gas increases to 12.0 atm and the temperature is raised to 125 C. What is the new volume of the gas?
Answer:
V2 = 0.223 LExplanation:
T1 = 25C = 298.15 K
P1 = 2.0 atm
V1 = 1.00 L
T2 = 125C = 398.15 K
P2 = 12.0 atm
V2 = ?
P1V1/T1 = P2V2/T2 must be changed to T2P1V1/T1/P2
398.15 x 2.0 x 1.00 ÷ 298.15 ÷ 12.0 = V2
V2 = 0.223 LSo 0.223 L is the answer!!
will lithium oxide ever be a liquid on any of the planet's or moon in our system? yes or no?
Answer:
no
Explanation:
trust me i got it right on my test
Lithium oxide ever be a liquid on any of the planet's or moon in our system - No.
What is lithium oxide?Lithium oxide is an inorganic compound with the chemical formula Li₂O, and it present in white solid form.
Lithium oxide is a strong base and on reacting with water will form lithium hydroxide. In this Lithium oxide compound atrong ionic bonds is present with great attraction force. Melting point of Lithium oxide is 1,438 degree celsius and no planet and moon have this much of temperature.
So, it is not possible to get liquid Lithium oxide in our system.
Hence, answer is NO.
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which vestigial structure do whales have? what is the function of this
Answer:
The pelvic bones of whales are one of the classic examples of a vestigial structure. In most animals, the pelvic bones are needed to be able to move the lower or rear set of limbs for the purpose of locomotion.
Which of the following is the name for two or more types of atoms that are chemically bonded together?
Compound
Colloid
Element
Solvent
Answer:
Compound
Explanation:
Compounds consists of atoms of two or more different elements that are chemically bonded together.
How do the numbers of metal and non metal elements compare with each other. What is the percentage
In a calorimeter, 10.0 g of ice melts at 0oC. The enthalpy of fusion of the ice is 334 J/g.
How much heat was absorbed?
A.) 0.33 kJ
B.) .34 kJ
C.) 33.4 kJ
D.) 334 kJ
Answer:
D
Explanation:
In the problem above it is
q = mass x heat fusion
q = 10 g x 334 J/g = 3340 J. Since the ice is absorbing heat it is + 334 J.
Answer:
3.34 kJ
Explanation:
took the test
Which is a diatomic molecule?
A) Ar
B) CO
C) CO2
D) NaCl
30 POINTS!!! PLEASE I'M VERY DESPERATE!
Please help me answer the questions, I'm horrible at reading and I can't focus, please help T-T
1) elements are composed of atoms, which are the tiny building blocks that compose matter.
2) Atoms resemble a solar system: the sun being the nucleus (protons and neutrons) and the electrons being the planets that orbit the nucleus.
3) Mostly everything (food, electronics, animals, plants, air)
4) The # of protons in the element
5) The same elements that were forged by stars are also present in us
HELPPP ASAPPP
A bar of gold occupies a volume of 17.0cm3 and has a mass of 34.5g. What is the density of that bar of gold?
A. 2.1 ml/g
B. 2.0 g/cm3
C. 0.49 g/cm3
D. 0.51 ml/g
Answer:
The answer is option BExplanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\[/tex]
From the question
mass of gold bar = 34.5 g
volume = 17 mL
We have
[tex]density = \frac{34.5}{17} \\ = 2.02941176...[/tex]
We have the final answer as
2.0 g/cm³Hope this helps you
A chemist conducts an experiment in which 2. 00 l of hydrogen gas is collected over water at 1. 00 ATM and 298. 15 K. The phrase over water means that the gas was collected by bubbling it into an inversed bottle filled with water which is sitting in a water bath. However the gas collected is now saturated with water vapor. The partial pressure of water vapor at 298. 15 K is 0. 0 300 ATM. Using Dalton's law calculate the pressure of the hydrogen gas in ATM
Answer:According to Dalton's law of partial pressures, the total pressure is equal to the sum of the partial pressures of each gas. In equation form, this looks like this ...
Pt = P1 + P2 + ...
Pt = total pressure
P1 = partial pressure of gas 1
P2 = partial pressure of gas 2
Explanation:
A compound has a molecular mass of approximately 295 g. It contains 40.68% Carbon, 5.12% Hydrogen, and 54.20% Oxygen. Calculate the empirical and molecular formula.
Arab cultures charted planets in the Dark Ages. Europeans helped establish the Sun-centered model of the solar system during the Renaissance. Russia and the U.S.A have discovered new features on planets using spacecraft in modern times.
This is an example of
A.
many cultures arguing about how the solar system works and all of their contributions being worthless.
B.
cultures wasting time by doing the same thing over and over throughout history.
C.
how contributions by many different cultures throughout history have advanced our understanding of the solar system.
D.
modern technology proving that earlier cultures could not contribute to our understanding of the solar system.
Since Russia and the U.S.A have discovered new features on planets using spacecraft in modern times, this is an example of: C. how contributions by many different cultures throughout history have advanced our understanding of the solar system.
What is a solar system?A solar system can be defined as a collection of the outer and inner astronomical or planetary bodies (planets) alongside the Moon that are in orbit around the Sun, in slightly elliptical orbits.
What is culture?Culture simply refers to the general way of life of people in a specific society or geographical area. This ultimately implies that, culture is a terminology which can be used to describe a sum total of the norms, beliefs, clothes, language, foods, and behaviors which a group of people that are living in a geographical area share in common.
In this context, we can reasonably infer and logically deduce that contributions by various cultures around the world have helped us to advance our understanding of the solar system.
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Consider the substances hydrogen (H2), fluorine (F2), and hydrogen fluoride (HF). Based on their molecular structures, how does the boiling point of HF compare with the boiling points of H2 and F2? The boiling point of HF is the boiling point of H2, and it is the boiling point of F2.
Answer:
the boiling point of HF is higher than H2 and F2
Explanation:
it is because inter molecular give is present in HF because of the Hydrogen bond present. Hydrogen bond is strong and will require much energy to break ,since no hydrogen bond is in the rest H2 and F2 has a low boiling point
The boiling point of a liquid depends upon the pressure of the surrounding. Here HF has higher boiling than the molecule of hydrogen and fluorine due to the presence of hydrogen bonding between 'H' and 'F' atoms.
What is boiling point?The temperature at which the vapor pressure of the liquid becomes equal to the atmospheric pressure of the liquid's environment is defined as the boiling point. A t this temperature, the liquid is converted into a vapour.
The intermolecular forces can be used to predict the relative boiling points. If stronger is the intermolecular force, the lower is the vapor pressure of the substance and the higher is the boiling point.
The order of intermolecular forces are:
H - bonding > dipole-dipole > London dispersion (Van der Waals)
Here HF has intermolecular hydrogen bonding which is not present in H₂ and F₂ and has high boiling point.
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How many moles are in 25 grams of oxygen?
The number of moles in 25 grams of oxygen is equal to 1.56 moles, as 16 grams of oxygen contain one mole.
What is a mole?A mole is a unit measurement that is used to calculate a large number of chemical entities such as atoms, molecules, ions, or other particular particles.
The mass of the one mole of any chemical element in the periodic table is called atomic mass and that of any compound is known as molar mass.
The number of chemical entities present in one mole was found to be equal to approximately 6.023 × 10 ²³ which is known as Avogadro’s number. In the calculation of the number of moles of a substance the given mass of the substance is divided by its molecular mass.
Given, the mass of the oxygen = 25 grams
As we know the atomic mass of oxygen is equal to 16g/mol
So 16 g of oxygen contains moles = 1
Then 25 g of oxygen will contain moles = 25/16 = 1.56 mol
Therefore, the moles of oxygen in 25 grams are equal to 1.56.
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Question 6 Not complete Points out of 2.0 Not flaggedFlag question Question text Separation can be achieved when a reaction occurs in a mixture. The resulting mixture will have one chemical species in a solution and the other chemical species as a solid. The mixture is centrifuged and the supernate is decanted into a separate test tube. Now the solid and solution are separated from each other. What reagent could you add to a mixture of Ag and Cu 2 to separate the two species
A reagent that could be added to a mixture of [tex]Ag^+[/tex] and [tex]Cu^{2+}[/tex] to separate this two species is hydrochloric acid (HCl).
What is a separation technique?A separation technique can be defined as a technique that is used to separate (convert) two or more mixture and solution of chemical substances into distinct products such as solutes, chemical compounds or elements.
In this scenario, a reagent that could be added to a mixture of [tex]Ag^+[/tex] and [tex]Cu^{2+}[/tex] to separate this two species is hydrochloric acid (HCl). As HCl is added to this mixture, a white precipitate would be formed by silver ions ([tex]Ag^+[/tex]) while the copper ion ([tex]Cu^{2+}[/tex]) would form a maroon precipitate.
In conclusion, the above confirmation test should be done when hydrochloric acid (HCl) is added to a mixture of [tex]Ag^+[/tex] and [tex]Cu^{2+}[/tex] as a reagent.
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4. One of Dr. Birdley's boxes has a volume
of 240 cm^3 and a density of 15 g/cm^3.
The mass of the box is
a) 225 g
b) 265 g
c)3600 g
d) 32 g
Density = Mass/Volume but it can also be rearranged to:
Mass = Volume x Density
Given in the question:
Volume - 240 cm3
Density - 15 g/cm3
Calculation
Mass = Volume x Density
= 240 x 15
= 3600g
Therefore, the mass of the box is 3600g so the answer is C.
Why are Punnett square used?
A. To visually help others Scientists understand physics
B. To help write a book on genetics
C. To determine the probability that an offspring would have a specific trait
D. To decode the human genome
Help please
Answer:
Your answer I believe will be C. To determine the probability that an offspring would have a specific trait.
how dose the scientific method help scientisis?
Answer:
It helps us to insure what will the current rate will be to those subject or nartual disaster can conquere
Summarize your main take away about water and hydrogen bonding.
Answer:
As water is boiled, kinetic energy causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas (steam or water vapor). When water freezes, water molecules form a crystalline structure maintained by hydrogen bonding.
Explanation:
the same
3. If the values for both mass and volume double,
the value for density will
How much concentrated 18 M sulfuric acid is needed to prepare 250 mL of a 6.0 M solution?
Answer:
I believe 83.33 mL is needed. :)
What are the 3 principles of the Kinetic molecular theory?
The kinetic molecular theory is a classical model that explained the movement of gas particles. It started about constant motion and collision, and the relation of KE with temperature.
What is Kinetic molecular theory?The Kinetic molecular theory was given by several scientists including Rudolf Clausius, Boltzman, Avogadro, and Graham. It stated several principles based on observations and experiments.
It stated that matter is composed of particles that are constantly in motion and have been known to show the constant perfect elastic collision due to the addition or removal of energy.
The kinetic energy of the particles is directly proportional to the temperature of the ideal gas condition and is involved in changes in the state of matter. Higher temperature exhibits more collisions.
Therefore, the Kinetic molecular theory stated about the particles, motion, collision, temperature, etc.
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Two same charges: As charge increases, potential energy
Increases
Decreases
Stays the same ?
Answer:
decreases
i think so
byeeee
Why does water roll off of dry ice?