Answer:
D. Nitrogen and Hydrogen
Explanation:
Answer: d
Explanation: took test
True/False: Units for gas density are grams/L
Answer:
false
Explanation:
(100 POINTS) When thermal energy (heat) is added to a reaction, it happens _________ (faster or slower)
When thermal energy (heat) is removed from a reaction, it happens _________ (faster or slower)
Answer:
1) faster
2) slower
Explanation:
Answer:
faster
Explanation:
A mixture cannot be reversed back to it’s original properties (true or false)
Answer:
False
Explanation:
A mixture is composed of two or more substances that are combined through physical means. It has NOT undergo any changes in its chemical properties. So, even though its appearance change, it can be reverted back.
Answer:
That answer would be false.
Explanation:
Depending on the type of mixture, you can separate it and reverse it back to its original properties through filtration, evaporation, distillation, and chromatography.
list in the following elements in order of smallest to largest atomic radius. F, Cl, Br, l
And which has a larger atomic radius?
Which statement best explains why the air pressure is greater at the poles than at the equator
Answer:
At the equator, the altitude is lower, and also because of the direct heating of sun rays on the surface, the temperature is much higher than at the poles. This makes the air near the surface hot and lighter and hence it rises up which results in lower air pressure.
Explanation:
Plz give me brainliest .-.
What is the ratio of aluminum atoms to oxygen atoms in aluminum oxide?
Answer:
Al2 O3 or 2:3
Explanation:
The aluminum oxide consists of two elements, which are oxygen atoms and aluminum atoms, and there are 2 aluminum atoms and 3 oxygen atoms in aluminum oxide. The ratio from aluminum atoms to oxygen atoms is 2:3.
There are two types of chemical compound one is covalent compound and other is ionic compound, covalent compound formed by sharing of electron and ionic compound formed by complete transfer of electron. Therefore, the ratio of aluminum atoms to oxygen atoms in aluminum oxide is 2:3.
What is chemical Compound?Chemical Compound is a combination of molecule, Molecule forms by combination of element and element forms by combination of atoms in fixed proportion.
An ionic compound is a metal and nonmetal combined compound. Ionic compound are very hard. They have high melting and boiling point because of strong ion bond. The ratio of aluminum atoms to oxygen atoms in aluminum oxide is 2:3. Aluminium oxide is an ionic compound.
Therefore, the ratio of aluminum atoms to oxygen atoms in aluminum oxide is 2:3.
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A balloon is a sphere with a radius of 5.0 m. The force of air against the walls of the balloon is 45 N. What is the air pressure inside the balloon? Surface area = 12.56 × radius² 1 Pa = 1 N/m² How would I solve this problem? What are the steps or a good way to remeber how to solve?
Answer:
0.127 N/m² or 0.127 Pa
Explanation:
From the question given above, the following data were obtained:
Radius (r) = 5 m
Force (F) = 40 N
Pressure (P) =.?
Next, we shall determine the Surface area of the sphere (i.e the balloon). This can be obtained as follow:
Surface area = 12.56 × r²
Radius (r) = 5 m
Surface area = 12.56 × 5²
Surface area = 12.56 × 25
Surface area = 314 m²
Finally, we shall determine the pressure as follow:
Force (F) = 40 N
Surface area = 314 m²
Pressure (P) =.?
Pressure = Force /Area
Pressure = 40/314
Pressure = 0.127 N/m² = 0.127 Pa
Therefore, the pressure inside the balloon is 0.127 N/m² or 0.127 Pa.
During evaporation, what causes certain liquid molecules to become vapor molecules? A. Decreased fluidity A. Increased viscosity A. Decreased kinetic energy A. Increased kinetic energy.
Answer:
The answer is A. Decreased Fluidity
Explanation:
Taking the test on preformance matters
In evaporation, particles of liquids take energy in the form of sunlight from the surrounding and then convert into vapor phase. Increased kinetic energy causes certain liquid molecules to become vapor molecules.
What is evaporation?Evaporation is a physical process in which the water in liquid state converts to gaseous state at the temperature below its boiling point. Evaporation happens before the boiling process.
Evaporation causes cooling effect in the surrounding. During summer when water is kept in earthen pot water cools, this is because of the evaporation process.
Evaporation is affected by temperature. As the temperature increases, kinetic energy of liquid molecules also increases and hence the rate of evaporation increases.
Therefore, increased kinetic energy causes certain liquid molecules to become vapor molecules.
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Electrons will pair up in an orbital only when
Answer:
All orbitals in the same sub level have one electron
Explanation:
All orbitals in the same sub level have one electron
How many atoms are in this formula? 2Fe
Answer:
two
Explanation:
There are two atoms in 2 Fe, more correctly written as 2Fe or Fe2. Both atoms are from the same element, iron.
Answer:
2
Explanation:
There are two atoms of the same element in 2Fe.
Hope this helps! :)
I need help with the 2nd part first gets brainlist
Answer:
7. 4H₂O
Elements: Hydrogen, Oxygen
Number of molecules: 4
Number of elements: 8 H, 4 O
Number of Atoms: 12
Explanation:
The elements are determined by the their symbol i.e. H = hydrogen.
The number of molecules is determined by the coefficient ( the number in front of everything, in this case 4).
The number of elements is determined by the coefficient and the subscripts. Multiply the coefficient by the subscript after each element. When there is no subscript, it is equal to 1. 4H₂ = 4x2 = 8; 4O = 4x1 = 4.
The number of atoms is all the individual elements added together. 8+4 = 12.
Which of the following is an example of very early scientific research?
sleeping in caves to avoid predation by animals
painting pictures and symbols on cave walls
making baskets from reeds
banging rocks together to see which make a spark and create fire
Answer:
banging rocks together to see which make make a spark and create fire painting pictures is an example of art and sleeping in caves is survival
stages of mitosis in order
Answer:
nucleus formed
prophase
metaphase
anaphase
telophase and cytokinesis
Which of the following is the correct model of C7H16?
A.
B.
C.
D.
Answer:
D
Explanation:
Option D gives the correct model of C7H16. From the option, one will discover that the model has 7 carbons in the backbone. If you count the attached hydrogen, you will discover that the hydrogen is 16 in total.
This model or skeletal structure of this element represents heptane. Heptane or n-heptane is known to be a straight-chain compound and an alkane. It's chemical formula can also be written as: H₃C(CH₂)₅CH₃ or C₇H₁₆.
This compound is known to be one of the main components of gasoline. It is known to be a volatile organic compound and a clear and colorless liquids with a petroleum-like odor.
Answer: D
Explanation: Just took the test
Element X has two naturally occurring isotopes. The isotope with mass 62.93 amu has a
relative abundance of 69.2%. The isotope with mass 64.93 amu has a relative
abundance of 30.8%. Calculate the average atomic mass of Element X. What is the
identity of Element X?
What volume will 250. mL of gas at STP occupy ig the pressure changes to 2.0 atmospheres and the temperature changes at 30 degrees Celsius
Answer:
it is 75 degrees
Explanation:
Volume is 138.7 mL.
The equation for calculation of volume is as follows:-
[tex]\frac{P_1V_1}{T_1} =\frac{P_2V_2}{T_2}[/tex]
STP:-
Temperature=273 K
Pressure=1 atm
[tex]\frac{1 atm\times250mL}{273 K} =\frac{2 atm\times V_2}{303\ K}\\V_2=138.7\ mL[/tex]
Hence, the volume is 138.7 mL.
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Mark is in charge of making change at his family's garage sale on a hot summer day. He runs low on change and brings out a jar of pennies from the house. He keeps the lid off of the jar. Later in the day, he notices that the pennies are hot. Which statement best explains what happened?\
Answer:
This question is incomplete
Explanation:
The question is incomplete without the options. However, when a metal (in this case what the pennies are made of) is left in direct contact with the heat from the sun, it conducts this heat and becomes hot. This process is called thermal conduction. The thermal energy is readily accepted by the material in which the pennies are made of thereby increasing the thermal energy of the penny coin which then makes the pennies hot after being left under the sun.
How does Newton’s laws explain motion
Explanation:
Newton's second law is a quantitative description of the changes that a force can produce on the motion of a body. It states that the time rate of change of the momentum of a body is equal in both magnitude and direction to the force imposed on it.
Which of the following elements are characterized by having full outermost s and p
orbitals?
F. Period 7
G.
Group 8A
H.
Inner transition elements
J.
Periods 4, 5, and 6
Answer:
Group 8A
Explanation:
Group 8A elements are characterized by having full outermost s and p orbitals. These elements are also known as the noble gases or inert gases. They occupy the last group on the periodic table.
They are known to have an outer shell configuration of ns² np⁶The configuration reveals that atoms of all the elements have completely filled orbitals in their outer shell sublevels. This accounts for the non-reactivity of elements in this group. Most of the elements in the group have high ionization energy and very low electron affinity values.Some of the elements in this group are Neon, Argon, Krypton, Xenon, and Radon.
How do I do this problem???
Answer:
i believe it's c
Explanation:
my reason is that if you look at the electrons 2 is the most comm
The Greek philosopher Empedocles proposed the idea that
ALL matter was made of_____
elements.
Answer:
the four elements fire, air, water earth
Explanation:
Identify the property of the matter described below.
Alcohol floats on top of the water.
A-pH
B-conductivity
C-density
D-luster
Answer: C.
Explanation: Alcohol floats on oil and water sinks in oil. Water, alcohol, and oil layer well because of their densities, but also because the oil layer does not dissolve in either liquid. The oil keeps the water and alcohol separated so that they do not dissolve in one another. ... Water sinks because it is more dense than oil.
A student decided to research primate psychology for their science project. They measured how long it took gorillas to adapt to their new habitat when moved from one zoo to another. They measured how long it took the new gorilla to interact regularly (more than 3 times per day) with the gorillas that already live there. Seven different cases were examined and the data collected. What can be said about the data? [GorillaTime to interact (days)12.523.138.343.352.763.273.4]
[
Gorilla 1 2 3 4 5 6 7 Time to interact (days) 2.5 3.1 8.3 3.3 2.7 3.2 3.4
]
A. The data is only measured to one decimal place, so it is not reliable.
B. The data falls within similar ranges so it may be reliable.
C. The data is reliable because there is only one outlier.
D. The data may not be reliable because there is an outlier.
Answer: the answer is D im pretty sure
Explanation:
Which of the following best describes how Thomson
concluded that electrons are present in all atoms.
a
The charge-to-mass ratio of electrons is always the
same constant, no matter which substances are
used in the cathode ray tube.
b The cathode ray was able to turn a wheel.
The cathode ray always bent toward a negatively
charged plate.
d
The charge-to-mass ratio is unique to each different
element.
Answer: A
Explanation:
The charge-to-mass ratio of electrons is always the same constant, no matter which substances are used in the cathode ray tube.
Explanation:
Thomson in his model of atom discussed that the atom consists of a negative charge particle termed electron randomly distributed in the positively charged sphere to balance the negative charge.His model of the atom was also known as the Plum pudding model of the atom. In which electrons are embedded in positive soup.He discovered electrons by conducting an experiment with cathode rays in which cathode rays emerging from the cathode were observed to be deflected towards the positively charged plate.He also conducted the same experiment with different metals (for anode and cathode) and gases and found out that the charge to mass ratio of the electron was regardless of the metals or gases used in the experiment.With this, he landed on the conclusion that these particles of cathode rays are the universal component of matter.So, from this, we can conclude that the charge-to-mass ratio of electrons is always the same constant, no matter which substances are used in the cathode ray tube describes Thomson's conclusion that electrons are present in all atoms.
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True or False: A Precipitate is a solid
that forms out of a liquid solution as a
result of a chemical reaction
Answer:
true because it undergoes a tranformation
Explanation:
3.58 x 1023 molecules of propane C8H8 would occupy how much space at STP
Answer: At STP, a mole of gas takes up 22.4 Liters. The 22.4 Liters/mole quantity can be derived from the Ideal Gas Law, PV = nRT, plugging in STP conditions for P and T, and solving for V/n, which gets 22.4 Liters/mole.
Explanation:
The bright red line from the emission spectrum of hydrogen has a wavelength of 657 nm. What is the energy, in joules, of a single photon of this light? 4.35 x 10–40 J 3.03 x 10–28 J 3.03 x 10–19 J 4.56 x 1014 J
Answer:
3.03 × 10^-19 J
Explanation:
The energy, E, of a photon of light can be calculated by using the formula:
E = hv
Where; E is energy in Joules,
h is Planck's constant {6.626×10^−34J}
v is frequency of light
For this question, the wavelength (λ) is given, not the frequency (v).
Hence, we use;
v= c/λ
Where v= frequency, c= speed of light (3×10^8m/s), λ= wavelength (657nm)
657nm = 657 × 10^-9m
v = 3×10^8/657 × 10^-9
v = 3/657 × 10^(8--9)
v = 0.00456 × 10^17
v = 4.56 × 10^14
Since frequency (v) = 4.56 × 10^14;
E = hv
E = 6.626×10^−34 × 4.56 × 10^14
E = 30.21 × 10^(-34+14)
E = 30.21 × 10^-20
E = 3.021 × 10^-19
Therefore, the energy of the photon of light is 3.02 × 10^-19 J
What explains the structure of metals and delocalized electrons?
A. the unit cell model
B. the geometric shape model
C. the covalent bond model
D. the electron sea model
What is the process whereby scientists check each other’s work?
A. defining the audience
B. conferencing
C. peer reviewing
D. writing
Answer:
peer reviewing
Explanation:
Its peer reviewing because there peers and there reviewing eachothers work
The process whereby scientists check each other’s work is peer reviewing.
What is peer group?Peer group are the groups of people of same age, same background with same interest.
In the peer reviewing process group of members will check, evaluate and correct each others work, which in turn help the members of the group to update their work.
Hence, option (c) is correct i.e. peer reviewing is the process whereby scientists check each other’s work.
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What is force and motion
Answer:
In physics, a force is any interaction that, when unopposed, will change the motion of an object. A force can cause an object with mass to change its velocity (which includes beginning moving from a state of rest), i.e., to accelerate. Force can also be described intuitively as a push or a pull.
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