A reaction where heat is added is a(n)
endothermic reaction
heterogeneous reaction
reversible reaction
in endothermic reaction heat is added
Use the periodic table to determine the electron configuration for aluminum (Al) and arsenic (As) in noble-gas notation.
Al:
[Ar]3s23p1
[He]2s22p63s23p1
[Ne]3s23p1
[Ne]3s23p2
Answer:
C
Explanation:
[Ne]3s23p1
Answer:
C
Explanation:
Which option(s) correctly shows an anion? Select all that apply.
Answer:
x
Explanation:
becaue neutron equal to mass num -atomic num
24 of 30
19
20
21
22
23
24
25
26
27
28
Which feature can distinguish between an elemental molecule and a compound molecule?
whether the molecule is formed from at least two atoms
O whether the molecule is formed by the sharing of electrons
O whether the molecule is a gas or a liquid
O whether the molecule is made from different types of atoms
Answer:
whether the molecule is formed from at least two atoms
Explanation:
A feature that distinguishes an elemental molecule and a compound molecule is whether the molecules are formed from at least two atoms.
An elemental molecule is a molecule that contains two or more of the same kind of elements.
A compound molecule contains two or more different kinds of molecules.
An example of elemental molecule is oxygen gas, O₂. An example of a compound molecule is water H₂O.A molecule is a unit of a compound that can represent such a compound.
Therefore, what distinguishes an elemental molecule from a compound molecule is whether a molecule forms from at least two atoms.
A solution contains 90 mL of methanol, 18 mL of propanol, and 2 mL of diethyl ether. Which is the solvent in this solution?
Answer:
Methanol
Explanation:
Forces are measured in
Newton
Watt
Mass
Grams
Answer:
A
Explanation:
Force can also be described intuitively as a push or a pull. A force has both magnitude and direction, making it a vector quantity. It is measured in the SI unit of newtons and represented by the symbol F.
CHEMISTRY! 50 POINTS! What is the original pressure of 20.0L of compressed gas if the pressure changes to 560.0mmHg when the volume is decreased to 15700mL?
Answer:
The answer is 439.60 mmHgExplanation:
To find the original pressure we use the formula for Boyle's law which is
[tex]P_1V_1 = P_2V_2[/tex]
where
P1 is the initial pressure
P2 is the final pressure
V1 is the initial volume
V2 is the final volume
Since we are finding the original pressure
[tex]P_1 = \frac{P_2V_2}{V_1} \\[/tex]
From the question
V1 = 20 L = 20,000 mL
P2 = 560.0mmHg
V2 = 15700mL
We have
[tex]P_1 = \frac{560 \times 15700}{20000} = \frac{8792000}{20000} = \frac{2198}{5 } \\ [/tex]
We have the final answer as
439.60 mmHgHope this helps you
List the official SI units
Answer:
The seven SI base units, which are comprised of:
Length - meter (m)
Time - second (s)
Amount of substance - mole (mole)
Electric current - ampere (A)
Temperature - kelvin (K)
Luminous intensity - candela (cd)
Mass - kilogram (kg)
Explanation:
Answer:
The seven SI base units, which are comprised of:
* Length - meter (m)
* Time - second (s)
* Amount of substance - mole (mole)
* Electric current - ampere (A)
* Temperature - kelvin (K)
* Luminous intensity - candela (cd)
* Mass - kilogram (kg)
Explanation:
Hope this helps :)
Plz, give me brainliest if u can... if I'm right, idrc if u do or not, just askin.
How many electrons are in the 4p orbital does Br possesses?
Answer:
5 electron
It contains 6 electrons in 2p orbital, 6 electrons in 3p orbital and 5 electron in 4p orbital.
how many oxygen atoms are there in six dinitrogen monoxide molecules? express your answer as an integer
Answer:
6 oxygen atoms
Explanation:
Step 1: Given data
Number of dinitrogen monoxide molecules (N₂O): 6
Number of oxygen atoms (O): ?
Step 2: Calculate the appropriate ratio
The ratio of dinitrogen monoxide molecules to oxygen atoms is 1:1.
Step 3: Use the ratio to calculate the number of oxygen atoms
6 molecule N₂O × (1 atom O/1 molecule N₂O): 6 atom O
What is the difference between a mixture and a compound ??
Answer:
Explanation:
Compound are substances which can be formed by chemically combining two or more elements. Mixtures are substances that are formed by physically mixing two or more substances.
What type of energy is elastic energy?
A. Kinetic energy
B. Chemical energy
C. Nuclear energy
D. Potential energy
ASAP
Answer:
D. potential energy
Explanation:
16.4 A cylinder of water contains oxygen in solution. The cross- sectional area of the cylinder is 2 cm2 and the length of the cylin- der is 5 cm. At one end of the cylinder the concentration of oxygern is maintained at 0.2 mol m-3, this concentration falls linearly to 0.05 mol m-3 at the other end of the cylinder. The diffusion con- stant of oxygen in water is 8 × 10-10 m2 s-1. How many moles of oxygen pass down this cylinder every second? What mass of oxy- gen passes down the cylinder each second?
Answer:
A) oxygen moles/sec = 48 * 10 ^-14 mol/sec
B) mass of oxygen = 1536*10^-14 grams
Explanation:
cross sectional area of cylinder = 2cm^2 = 2 * 10^-4 m^2
length of cylinder = 5 cm = 0.05 m
concentration at one end = 0.2 mol m^-3
concentration falls linearly at other end = 0.05 mol m^-3
Diffusion constant of oxygen = 8 * 10^-10 m^2 s^-1
A ) Number of moles of oxygen passing every second
N = A * D * [tex]\frac{dc}{dt}[/tex] ------- ( 1 )
A = area , D = diffusion constant, [tex]\frac{dc}{dt}[/tex] = rate of change of diffusion
dc /dt = ( 0.2 - 0.05 ) / 0.05 = 3 mol m^-4
back to the equation
N = ( 2 * 10^-4 ) * ( 8 * 10^-10 ) * ( 3 ) = 48 * 10 ^-14 mol/sec
B) Mass of oxygen passing down the cylinder each second
This can be obtained by converting : 48 * 10^-14 moles to grams
1 mole of oxygen = 32 grams of oxygen
therefore : 48 * 10^-14 moles of oxygen = ( 32 * (48*10^-14) = 1536*10^-14 grams
At STP, a 50-gram sample of H20(I) and a 100-gram sample of H20(I) have
Answer:
(1) the same chemical properties .
Explanation:
Hello!
In this case, among the options:
(1) the same chemical properties
(2) the same volume
(3) different temperatures
(4) different empirical formulas
We can see that they have the same chemical properties as they at the same conditions, same type of bond (polar), molecular geometry, bond angle (104.5 °) and so on. Nevertheless, at STP (1 atm and 273.15 K) they do not have the same volume since the larger the mass, the larger the volume, they have the same temperature and the both of them are H₂O.
It means that the answer is (1) the same chemical properties .
Best regards.
this happens in massive star which convert hydrogen into helium?
Answer:
nucleosynthesis. A star's mass determines what other type of nucleosynthesis occurs in its core (or during explosive changes in its life cycle).
You are given a sample of a Group II metal chloride, but the identity of the metal is unknown. Knowing that all Group II metal chloride compounds have the general formula, MCI2 and that the percentage of chlorine in the compound is 34.1%, what is the identity of the unknown substance?
Answer:
The identity of unknown substance is Barium.
Explanation:
The given compound has a formula of MCl2. And the percentage of chlorine in this compound is said to be 34.1 %. But, we know that the mass of chlorine in this compound is, 35.5*2 = 71 g
Therefore, if we let x be the total mass of the compound, then:
34.1% of x = 71 g
(0.341)x = 71 g
x = 71 g/0.341
x = 208.2 g
Hence, the mass of other atom M, must be:
M = x - 71 g
M = 208.2 g - 71 g
M = 137.2 g
Now, we look into periodic table in group II. We find that the element is Barium with atomic mass of 137 g.
The identity of unknown substance is Barium.
Barium forms a metal chloride whose percentage of chlorine is 34.1 %. The unknown substance is barium chloride.
We have a Group II metal chloride with a general formula MCl₂. The molar mass of Cl⁻ is 35.45 g/mol. The mass of 2 moles of Cl⁻ is:
[tex]2 mol Cl^{-} \times \frac{35.45g Cl^{-} }{1mol Cl^{-} } = 70.90g Cl^{-}[/tex]
70.90 g represents 34.1% of 1 mole of MCl₂. The molar mass of MCl₂ is:
[tex]70.90gCl^{-} \times \frac{100gMgCl_2}{34.1gCl^{-} } = 208gMgCl_2[/tex]
208 g of MCl₂ contains 70.90 g of Cl⁻. The mass of M²⁺ in 1 mole of MCl₂ is:
[tex]mMCl_2 = mCl^{-} + mM^{2+} \\\\mM^{2+} = mMCl_2 - mCl^{-} = 208g-70.9 g = 137.1 g[/tex]
Barium has a molar mass of 137.3 g/mol, so M must be barium. The unknown substance is barium chloride.
Barium forms a metal chloride whose percentage of chlorine is 34.1 %. The unknown substance is barium chloride.
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What is the energy of a photon of red light having a frequency of 3.08 x 10^14 HZ?
Answer:
2.04 x 10⁻¹⁹J
Explanation:
Given parameters:
Frequency = 3.08 x 10¹⁴Hz
Unknown:
The energy of the photon = ?
Solution:
The energy of a photon is given as;
E = hf
Where h is the planck's constant
f is the frequency
Insert the parameters and solve;
E = 6.63 x 10⁻³⁴ x 3.08 x 10¹⁴
E = 20.4 x 10⁻³⁴⁺¹⁴
E = 20.4 x 10⁻²⁰ = 2.04 x 10⁻¹⁹J
Answer:
2.97*10-19 j
Explanation:
E=Energy of photon
H=Planck constant=6.626*10-34
V=Frequency of photon
we can plug what we already know E=(6.626*10-34)(4.48*10 14)
The basis of the VSEPR model of molecular bonding is __________. Question 1 options: atomic orbitals of the bonding atoms must overlap for a bond to form regions of electron density in the valence shell of an atom will arrange themselves so as to maximize overlap electron domains in the valence shell of an atom will arrange themselves so as to minimize repulsions regions of electron density on an atom will organize themselves so as to maximize s-character Question 2 (1 point)
Answer:
Electron domains in the valence shell of an atom will arrange themselves so as to minimize repulsions
Explanation:
In accordance with VSEPR theory, the electron domains or electron pairs on the valence shell of the central atom in a molecule always position themselves as far apart in space as possible in order to minimize repulsions.
Recall that according to VSEPR theory, the shape of a molecule depends on the number of electron pairs or electron domains on the valence shell of the central atom of the molecule, both lone pairs and bond pairs. Lone pairs are known to cause more repulsions than bond pairs.
How is color a physical change
Answer:Physical changes involve states of matter and energy. No new substance is created during a physical change, although the matter takes a different form. The size, shape, and color of matter may change. Physical changes occur when substances are mixed but don't chemically react.
Explanation:
4. Solve the following heat flow problem, being sure to show all your work (you may either type your
work or insert an image): Find the specific heat of 402 grams of graphite that absorbs 1136) of heat
energy as it changes temperature from 26°C to 30°C.
Answer should be 0.7J/gC
Answer:
0.70 J/g.°C
Explanation:
Step 1: Given data
Mass of graphite (m): 402 gHeat absorbed (Q): 1136 JInitial temperature: 26°CFinal temperature: 30 °CSpecific heat of graphite (c): ?Step 2: Calculate the specific heat of graphite
We will use the following expression.
Q = c × m × ΔT
c = Q / m × ΔT
c = 1136 J / 402 g × (30°C - 26°C)
c = 0.70 J/g.°C
how many atoms are in 20 grams of aluminum
Answer:
4.5 × 10²³ number of atoms Al
Explanation:
Given data:
Mass of Al = 20 g
Number of atoms of Al = ?
Solution:
The given problem will solve by using Avogadro number.
'It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance" .The number 6.022 × 10²³ is called Avogadro number.
We will calculate the number of moles of Al first:
Number of moles = mass/molar mass
Number of moles = 20 g/ 27 g/mol
Number of moles = 0.74 mol
1 mole = 6.022 × 10²³ number of atoms
0.74 mol × 6.022 × 10²³ number of atoms / 1 mol
4.5 × 10²³ number of atoms Al
The required number of atoms is [tex]4.46\times 10^{23}[/tex]
Atomic Weight:Atomic weight, also called relative atomic mass, ratio of the average mass of a chemical element’s atoms to some standard.
Given that,
Mass=[tex]20[/tex] grams
1 mole of aluminum [tex]= 27g = 6.023\times10^{23}[/tex] number of atoms 27g of aluminum contains [tex]6.023\times10^{23}[/tex] a number of atoms.
Therefore,20 grams the number of atoms is,
[tex]6.023\times10^{23}\times\frac{20}{27} =4.46\times10^{23}[/tex]
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Which best describes the purpose of a controlled experiment?
to make sure the results of the experiment support the hypothesis
to prevent a dangerous condition resulting from a reaction
to examine whether one variable causes a change in another
to prevent an undesired change in a variable
Answer: To examine whether one variable causes a change in another
Explanation:
Active and inactive volcano in philipines?
355 volcanoes in the Philippines are inactive.
24 volcanoes are active
Answer:
TAAL ACTIVE
MAOUNT BALUGAO INACTIVE
Explanation:
If 298 mL of 0.575 M CuCl2 is diluted into 750 mL, what is the concentration of new solution?
Answer:
The answer is 0.228 MExplanation:
To find the concentration of new solution we use the formula
[tex]C_1V_1 = C_2V_2[/tex]
where
C1 is the concentration of the stock solution
V1 is the volume is the volume of the stock solution
C_2 is the concentration of the diluted solution
V2 is the volume of the diluted solution
Since we are finding the the concentration of new solution
[tex]C_2 = \frac{C_1V_1}{V_2} \\[/tex]
From the question
C1 = 0.575 M
V1 = 298 mL
V2 = 750 mL
We have
[tex]C_2 = \frac{0.575 \times 298}{750} \\ = 0.228466666...[/tex]
We have the final answer as
0.228 MHope this helps you
40. Which of these is an example of an
anhydrous compound?
A) H2O
C) CuSO4.5H2O
B) CaSO4
D) CaSO4 · 2H2O
Explanation:
CuSO4.5H2O and CaSO4.2H2O
Answer:
CaSO4 is an example of anhydrous compound
Reason:
Calcium Sulphate (CaSO4) does not contain water in its crystal structure, unlike other minerals.
How many atoms of H are in 11 moles of H2O
Answer:
1.325×10²⁵
Explanation:
1 mole of H2O has 2 mole of H atom
11 mole of H20 has 22 mole of H atom
we know
1 mole=6.023×10²³ atom
hence 22mole H =22×6.023×10²³
=1.325×10²⁵
Plz help don’t understand.
Answer:
the last one i think
Explanation:
A conclusion in science states whether or not a hypothesis is correct
or not?
Answer:it do not states
Explanation:
help please need now
Answer:
it is second one
Explanation:
thanks
What is a product made from nonrenewable resources?
a shirt made from natural plant fibers
a bookshelf made from wood
a nail made from the metal iron
a paintbrush made from horse hair
Answer:
C. a nail made from the metal iron
Explanation:
I did the test.
The product made from non-renewable resources is nail made from the metal iron.
What are nonrenewable resources?Non renewable resources are materials that do not replenish themselves but they are easily exhausted or diminished after a period of time.
Therefore, The product made from non-renewanleable resources is nail made from the metal iron.
Learn more about nonrenewable resources below.
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