Answer:
The exposed metal rusts is an example of a chemical change because rust is an example of a chemical change in objects for example bicycles, scooters, etc.
The data table shows the number of pumpkin seeds that germinate at different temperatures. What is the median number of seeds that germinate at 24C?
A. 80.5 B. 82 C. 78.5 D. 80
Answer:
Explanation:
80
Reactions are classified as either exothermic or endothermic. . ____________ reactions feel hot (e.g., a burning campfire), whereas _________reactions feel cool.
Answer:
Exothermic reactions feel hot
Endothermic reactions feel cool
Explanation:
In an exothermic reaction, heat is given out by the system. The energy of the reactants is greater than that of the products hence the excess energy is given off as heat. The reaction vessel feels hot.
In an endothermic reaction, the energy of products is greater than that of the reactants hence energy is taken into the system and the reaction vessel feels cool.
which of the following Ph levels would indicate the weakest base?
15
8
6
2
Answer:
8
Explanation:
7 is neutral any anything above it is basic and anything below is acidic which means 8 would be the lowest base
Answer:
The pH of a weak base falls somewhere between 7 and 10.
Explanation:
Like weak acids, weak bases do not undergo complete dissociation; instead, their ionization is a two-way reaction with a definite equilibrium point
If 1.4434 moles of H2O are produced, how many moles of N2 will also be produced?
Answer:
1 gram of N2 is equal to 0.035697202053303 mole. i dont know the rest but intried to help
. hopefully this will give you someone else a starting point. goodluck
If 5.00g of iron metal is reacted with 0.950g of Cl2 gas, how many grams of ferric chloride (FeCl3) will form?
Answer:
1.45g of FeCl3
Explanation:
The equation of the reaction is given as;
2Fe + 3Cl2 --> 2FeCl3
2 mol of Fe reracts with 3 mol of Cl2 to form 2 mol of FeCl3
Upon converting to mass using;
Mass = Number of moles * Molar mass
( 2 * 55.85 = 111.7g ) of Fe reacts with ( 3 * 71 = 213g ) of Cl2 to form ( 2 * 162.2 = 324.4g) of FeCl3
Cl2 is the limiting reactant as it determines how much of FeCl3 is formed
213g of Cl2 = 324.4g of FeCl3
0.950g of Cl2 = x
x = (0.950 * 324.4 ) / 213
x = 1.45g of FeCl3
how can you tell where sugar enters the blood stream
please help asap
Answer:
Sugar can't enter cells directly , so when blood sugar level rises, ... signal for the release of insulin into the bloodstream.
Explanation:
yes when the sugar enter the bloodstream it may slowly slowly effect in your body and it may causes diabetes
How does the motion of particles in the sun’s plasma compare to the motion of particles in a solid?
Particles in both the plasma and a solid move around to fill available space.
Particles in the plasma move randomly, but particles in a solid vibrate in one place.
Particles in the plasma have low kinetic energy, but particles in a solid have high kinetic energy.
Particles in both the plasma and a solid are made up of fast-moving electrons and cations.
Answer:
Particles in the plasma move randomly, but particles in a solid vibrate in one place.
Explanation:
You need to make an aqueous solution of 0.192 M barium sulfide for an experiment in lab, using a 500 mL volumetric flask. How much solid barium sulfide should you add?
Answer:
Explanation:
Molecular weight of barium sulphide = 169
500 mL of .192 M barium sulfide = .5 x .192 moles of barium sulphide
= .096 moles of barium sulfide
= .096 x 169 gram of barium sulfide
= 16.22 grams of barium sulfide .
We shall have to add 16.22 gram .
The empirical formula of CBr2 has a molar mass of 515.46 g/mol. What is the molecular formula of this
compound
Answer:
C3Br6
Explanation:
C= (1 X 12.011) = 12.011
Br= (2 X 79.904)= 159.808
159.808+12.011 = 171.819
515.46 divided by 171.819 = 3.00
so you mulitpy CBr2 by 3 which gives you C3Br6
In which atmospheric layer is the ozone layer?
A.troposphere
B.mesosphere
C.stratosphere
D.thermosphere
Answer:
stratosphere
Explanation:
contains a high concentration of ozone in relation to other parts of the atmosphere, although still small in relation to other gases in the stratosphere.
Answer:
stratosphere
Explanation: Most atmospheric ozone is concentrated in a layer in the stratosphere, about 9 to 18 miles (15 to 30 km) above the Earth's surface. Ozone is a molecule that contains three oxygen atoms.
An atom of beryllium has 4 protons, 4 electrons, and 5 neutrons. What is its mass number?
Answer:
D. 9.
Explanation:
Mass number of an atom is the sum of the proton number and neutron number. For Be, the protons are 4 and neutrons are 5. So, we get 9 by adding them.
The equilibrium constant for A + 2B → 3C is 2.1 * 10^-6
Determine the equilibrium constant for 2A + 4B → 6C.
a- 4.2 * 10^-6
b- 4.4 * 10^-12
c- 2.3 *10^11
d- 1.8 *10^-11
e- None of these
Answer:
b- 4.4 * 10^-12.
Explanation:
Hello.
In this case, as the reaction:
A + 2B → 3C
Has an equilibrium expression of:
[tex]K_1=\frac{[C]^3}{[A][B]^2}=2.1x10^{-6}[/tex]
If we analyze the reaction:
2A + 4B → 6C
Which is twice the initial one, the equilibrium expression is:
[tex]K_2=\frac{[C]^6}{[A]^2[B]^4}[/tex]
It means that the equilibrium constant of the second reaction is equal to the equilibrium constant of the first reaction powered to second power:
[tex]K_2=K_1^2[/tex]
Thus, the equilibrium constant of the second reaction turns out:
[tex]K_2=(2.1 * 10^{-6})^2\\\\K_2=4.4x10^{-12}[/tex]
Therefore, the answer is b- 4.4 * 10^-12.
Best regards.
why ice melt into water
what particular distribution you share in earth?
Answer:
trees
Explanation:
we plant trees hindi sure kung tama to hihi
Which of the three crowns was made of gold? Explain:
Answer:
I need more context. Maybe add a picture.
Explanation:
Answer:
Crown B
Explanation:
because the density of gold is 19.3 and the density of the crown is 19.29.
what does celery, a wooden spoon, and oil/gasoline have in common?
Answer:
All of them are organic compounds which have carbon as their main atom in the structure.
Explanation:
Hello.
In this case, since organic chemistry is the study of all the compounds having the carbon atom as their main atom, all the vegetables, animals, an in general, living things are composed by lipids, proteins, and other organic substances with this feature. Moreover, wood-based materials are mainly composed by lignin which is an organic polymer also having carbon as the main atom. In addition, oil and gasoline are organic chemical compounds with a lot of applications in daily life which also contain carbon atoms in their structure.
In such a way, a celery, a wooden spoon, and oil/gasoline have the carbon atom in common as their main atom in their chemical structures.
Best regards.
Cations are always
Question Blank
than the neutral atom.
Hydrogen has 3 isotopes. Hydrogen 1, Hydrogen 2 and Hydrogen 3. What is the difference between these 3 is isotopes
Answer:
Number of neutrons
Explanation:
All have one single proton. Hydrogen has no neutrons. Hydrogen 2 or deuterium has 1 neutron. Hydrogen 3 or tritium has 2 neutrons.
Which of the following substances would have the greatest ductility?
A. Fe(s)
B. SiO2(s)
C. C(s)
D. NaCl(s)
Fe(s) would have the greatest ductility.
What is ductility?Ductility is the capability of a fabric to be drawn or plastically deformed without fracture. it's far therefore a demonstration of how 'gentle' or malleable the fabric is. The ductility of steel varies relying on the sorts and levels of alloying factors gift.
What are malleability and ductility?Ductility is the property of metallic associated with the capability to be stretched into twine without breaking. Malleability is the assets of metallic associated with the ability to be hammered into thin sheets without breaking. The outside force or strain is tensile pressure.
Learn more about ductility here https://brainly.com/question/496496
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Which option BEST explains how thermal equilibrium interacts with heat transfer between particles?
a
Thermal equilibrium stops the transfer of energy in just one direction when both objects reach the same temperature, but allows their particles to continue transferring that energy back and forth.
b
Thermal equilibrium always transfers energy from the hotter object to the colder one, and increases the energy and speed of moving particles in both objects as the temperature decreases.
c
Thermal equilibrium helps the transfer of energy between the particles of some materials better than others, but always stops the transfer of energy in materials like plastic and wood.
d
Thermal equilibrium quickly transfers energy back to the particles of the object that was originally hotter, and requires that the particles in both objects have reached equal energy and density.
Answer:
Thermal equilibrium stops the transfer of energy in just one direction when both objects reach the same temperature, but allows their particles to continue transferring that energy back and forth.
Explanation:
a. The transfer of energy occurs until both objects reach thermal equilibrium. But particles are always moving and crashing with each other. TRUE.
b. The heat transfer occurs from the hotter object to the colder one but moving of particles descreases with temperature decreasing. FALSE.
c. Plastic and wood have a poor quality to transfer energy but there is no material that "stops" perfectly the transfer of energy. FALSE.
d. The heat is transferred from the particles of the hotter object to the particles of the colder one. FALSE
On average, about ____________ of incoming solar radiation is reflected back to space.
A 50%
B 30%
C 20%
D 10%
Which is a chemical property of milk
A. Milk has a ph ranging from 6.4 to 6.8
B. Milk spoils when left unrefrigerated
C. Milk boils at about 212F
D. Milk curdles when mixed with vinegar
Answer:
C. Milk boils at about 212F
Explanation:
The principal constituents of milk are water, fat, proteins, lactose (milk sugar) and minerals (salts). Milk also contains trace amounts of other substances such as pigments, enzymes, vitamins, phospholipids (substances with fatlike properties), and gases.
Use the drop-down menu to complete the statement.
Atoms of elements in the same group have the same number of
. This is why they have similar chemical properties.
Answer:
valence electrons
Explanation:
other guy was close enough
Atoms of elements in the same group have the equal number of valence electrons. That is why they have similar chemical properties.
Why does the element in the same group have similar chemical behavior?The chemical properties of elements depend on the number of valence electrons in their outermost shell. Those elements which are placed in the same group in the periodic table have the same number of valence electrons.
Therefore, elements present in the same group of the modern periodic table have similar chemical behavior.
The elements having a similar valence shell electronic configuration in their atoms are arranged in the same group of the periodic table. These valence electrons decide the chemical properties and reactivities of the chemical elements.
For example, all the elements in group 1 of the periodic table have one electron in their valence shell and all the elements present in group 17 have seven electrons in their valence shell.
Learn more about elements with similar chemical behavior, here:
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If 25.6 mL isopropyl alcohol fully decomposes, what mass of H2 is formed? The density of isopropyl alcohol is 0.785 g/mL. g
Answer:
The correct answer is 0.67 g H₂
Explanation:
Isopropyl alcohol (C₃H₇OH) can decompose to give acetone (C₂H₆OH) and hydrogen gas (H₂) according to the following chemical equation:
C₃H₇OH (g) ⇒ C₂H₆CO(g) + H₂(g)
We can calculate the initial mass of isopropyl alcohol from the density and volume data:
density = m/V = 0.785 g/mL
⇒ m = density x V = 0.785 g/mL x 25.6 mL = 20.096 g C₃H₇OH
According to the chemical equation 1 mol of C₃H₇OH gives 1 mol H₂. The molar mass of C₃H₇OH is:
molar mass C₃H₇OH = (12 g/mol x 3) + (1 g/mol x 7) + 16 g/mol + 1 g/mol = 60 g/mol
molar mass H₂ = 1 g/mol x 2 = 2 g/mol
So, we obtain: 2 g H₂ from 60 g C₃H₇OH. We multiply this stoichiometric ratio (2 g H₂/60 g C₃H₇OH) by the initial mass of C₃H₇OH to obtain the mass of H₂ is formed:
20.096 g C₃H₇OH x (2 g H₂/60 g C₃H₇OH) = 0.6698 g ≅ 0.67 g H₂
The table below shows first ionization energies of some of the elements in the periodic table.Based on the information in the table, what can you conclude about the ability of noble gases to undergo ionization?
a
Noble gases give up first electrons easily compared to elements in other groups.
b
Noble gases cannot be forced to give up electrons.
c
The willingness of a noble gas to give up electrons decreases from top to bottom within the group.
d
It is more difficult to remove electrons from a noble gas than it is to remove electrons from elements in other groups.
Answer:
It is more difficult to remove electrons from a noble gas than it is to remove electrons from elements in other groups.
Explanation:
Let me restate here that in the noble gases, the outermost shell is filled. Owing to this full shell, noble gases has the outermost eight electrons required for any specie to attain stability.
It is very difficult to remove an electron from a closed shell. This is why the first ionization energy of noble gases is usually far higher than that of elements from other groups.
What is the frequency of a wave having 4.90 x 10 -12 J of energy?
Answer:
The answer is
[tex] \huge 7.40 \times {10}^{21} Hz[/tex]
Explanation:
To find the frequency of the wave we use the formula
[tex]f = \frac{E}{h} \\ [/tex]
where
E is the energy
f is the frequency
h is the Planck's constant which is
6.626 × 10-³⁴ Js
From the question
E = 4.90 × 10-¹² J
So we have
[tex]f = \frac{4.90 \times {10}^{ - 12} }{6.626 \times {10}^{ - 34} } \\ [/tex]
We have the final answer as
[tex]7.40 \times {10}^{21} \: \: Hz[/tex]
Hope this helps you
__________ have the lowest ionization energies of the groups listed
PLZ HELP I'LL AWARD BRAINLIEST
Answer: have the lowest ionization energies of the groups listed
PLZ HELP I'LL AWARD BRAINLIEST
Explanation:
What does a dissolved salt look like?
Answer:(trick question) once the salt has dissolve in the water it is no longer visible
Thank you! have an amazing day.
Identify the correct net ionic equation for the reaction that occurs when solutions of Pb(NO3)2 and NH4Cl are mixed.
Answer:
Pb2+(aq) + 2Cl–(aq) ----> PbCl2(s)
Explanation:
The net ionic equation shows the main reaction that takes place in a system. Hence, a net ionic equation focusses only on those species that actually participate in the reaction.
For the reaction between Pb(NO3)2 and NH4Cl , the net ionic equation is;
Pb^+(aq) + 2Cl^-(aq) ---> PbCl2(s)
The correct net ionic equation for the reaction that occurs when solutions of Pb(NO₃)₂ and NH₄Cl are mixed is
Pb⁺(aq) + 2Cl¯(aq) —> PbCl₂(s)To know the the correct net ionic equation for the reaction that occurs when solutions of Pb(NO₃)₂ and NH₄Cl are mixed, we shall write the net ionic equation for the reaction. This is illustrated below:
Pb(NO₃)₂(aq) —> Pb⁺(aq) + NO₃¯(aq)
NH₄Cl(aq) —> NH₄⁺(aq) + Cl¯(aq)
Pb(NO₃)₂(aq) + NH₄Cl(aq) —>
Pb⁺(aq) + NO₃¯(aq) + NH₄⁺(aq) + Cl¯(aq) —> PbCl₂(s) + NO₃¯(aq) + NH₄⁺(aq)
Cancel the spectator ions (i.e NO₃¯ and NH₄⁺) and write 2 before Cl¯ to obtain the net ionic equation as shown below:
Pb⁺(aq) + 2Cl¯(aq) —> PbCl₂(s)Thus, the correct net ionic equation for the reaction that occurs when solutions of Pb(NO₃)₂ and NH₄Cl are mixed is
Pb⁺(aq) + 2Cl¯(aq) —> PbCl₂(s)Learn more: https://brainly.com/question/21883718
10. Which of the following is NOT correctly matched?
A. Salt: Na and C: Element
B. Water: H and O: Corapound
C. Carbon dioxside: C and O: Compound
D. Magnesium chloride: Mg and C: Compound
Answer:
A. because salt : Na and Cl, not C