Answer:
Na ·
Explanation:
Hello!
In this case, since the Lewis dot structure of any element illustrates the number of valence electrons at the outer shell; we can set up the electron configuration of sodium to obtain:
[tex]Na^1^1\rightarrow 1s^2,2s^2,2p^6,3s^1[/tex]
We can see there is only one valence electron, for that reason the Lewis dot structure is:
Na ·
Whereas the dot represents the valence electron.
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Give an example of a change that would be a chemical change but not a physical change.
Answer:
digesting food
Explanation:
you dont see it
Answer:
When you mix two substances and it either smokes, bubbles, gets warmer, or created a new substance.
I need help with this!
Answer:
2.68 cm^3
Explanation:
Density= Mass/Volume
so...
8.96 g/cm^3 = 24.01 g/ V
and then u solve so it would be 2.68 cm ^3
((:
If an object gets smaller due to a change in state, what happens to its volume? How will this affect its density?
Answer:
the volume of a object will go down but the density stays the same
How many moles of Iron (Fe) can be produced form 20 moles of carbon
(C)?
2Fe2O3 + 3C —— 4Fe + 3C02
Moles of Fe produced = 40 moles
Further explanationGiven
Reaction
2Fe2O3 + 3C —— 4Fe + 3C02
20 moles of C
Required
moles of Fe
Solution
The reaction coefficient in a chemical equation shows the mole ratio of the reacting compounds (reactants and products)
From the reaction, mol ratio of Fe : C = 4 : 3, so mol Fe :
= 4/2 x mol C
= 4/2 x 20
= 40 moles
What amount of heat, in kJ, is required to vaporize 163.45 g of ethanol (C₂H₅OH)? (∆Hvap = 43.3 kJ/mol)
Answer:
Amount of heat required = 153.62 J
Explanation:
Given:
Mass = 163.45 g
∆Hvap = 43.3 kJ/mol
Molar mass C₂H₅OH = 46.07 g/mol
Find:
Amount of heat required
Computation:
Amount of heat required = Number of moles x Molar mass C₂H₅OH
Amount of heat required = [163.45/46.07][43.3]
Amount of heat required = 153.62 J
All of the following can reduce the risk of heart attacks except which one?
A. Regular exercise
B. Sleep deprivation
C. Low dose apirin
D. Diabetes control
can someone help me?
Answer:
Itz 4 and watch the superbowl please.
Explanation:
can someone help me with this?
Answer:
The growth of any plant is controlled by many factor and it depends on them.
Explanation:
The words are sorted according to their genetic factors and the environment factors by the category on which they effect and impact the growth of a plant.
Genetic factor :
Waxy leaves, bad tasting leaves, disease, leaf structure, types of stem, plant structure, reproduction, types of roots.
Environment factor : sunlight, drought, fire, flood, heat wave, insects, wind, space, pH of soil, temperature, pollution, terrain, soil conditions, lack of air.
the law of conservation of mass
Answer: The Law of Conservation of Mass dates from Antoine Lavoisier's 1789 discovery that mass is neither created nor destroyed in chemical reactions. In other words, the mass of any one element at the beginning of a reaction will equal the mass of that element at the end of the reaction.
Explanation:
The higher priority has been given for the use of biogas energy in Nepal, give two reasons.
Answer:
Biogas units provide a cleaner and safer source of energy, enabling rural families to produce their own electricity, heat, and fertilizer. One advantage of these plants is that they can be used in exactly the place they're needed, thereby averting the need for extensive, costly power landlines.
You buy butter $3.31 a pound one portion of onion compote requires 1.7 oz of butter how much does the butter for one portion cost round to the nearest cent
Answer:
The butter for one portion cost is $0.35.
Explanation:
If expending 3500 kcal is equal to a loss of 1.0 lb, how many days will it take Charles to lose 5.0 lb? Express your answer to two significant figures. Charles consumes 1800 kcal per day.
Answer:31 days
Explanation:
3500kcal/lb x 5lb =17500
1800-1230=570
17500/570=30.70
Round up =31
This question involves the concepts of energy, weight, and time.
It will take Charles "9.7 days" to lose 5.0 lb.
TIME TO LOSE WEIGHTSince the loss of 1.0 lb weight requires expending 3500 kcal energy. Therefore, by using the unitary method,
1.0 lb loss = 3500 kcal
(5)(1.0) lb loss = (5)(3500 kcal)
5.0 lb loss = 17500 kcal ----- eqn(1)
Now, the time required to consume 1800 kcal is 1 day. Hence, by the unitary method,
1800 kcal = 1 day
1 kcal = [tex]\frac{1}{1800}\ day[/tex]
17500 kcal = [tex]\frac{17500}{1800}[/tex] day
17500 kcal = 9.7 days ------ eqn(2)
Comparing eqn (1) and eqn (2)
5.0 lb loss = 9.7 days
Learn more about energy here:
https://brainly.com/question/1932868
Consider four beakers labeled A, B, C, and D, each containing an aqueous solution and a solid piece of metal. Identity the beakers in which a chemical reaction will occur and those in which no reaction will occur. Mn(s) Ca(NO3)2(aq) KOH(aq) Fe(s) Pt(NO3)2(aq) Cu(s) Cr(s) H2SO4(aq)
Answer:
1. Mn(s) + Ca(NO₃)₂(aq) ----> No reaction
2. KOH(aq) + Fe(s) ----> No reaction
3. Pt(NO₃)₂(aq) + Cu(s) ----> Reaction occurs
4. Cr(s) + H₂SO₄(aq) ----> Reaction occurs
Explanation:
The activity series of metals is a series that arranges metals in order of reactivity from highest to lowest. It is used to determine which metal will displace another in a single displacement reactions, whereby a metal A, will replace or be replaced by another metal B in an aqueous solution depending on their relative positions in the activity series.
Considering the given reactions:
1. Mn(s) + Ca(NO₃)₂(aq)
2. KOH(aq) + Fe(s)
3. Pt(NO₃)₂(aq) + Cu(s)
4. Cr(s) + H₂SO₄(aq)
Reaction 1 will not occur because manganese, Mn, is lower than calcium, Ca, in the activity series of metals and cannot displace it from aqueous solutions.
Reaction 2 will not occur since iron, Fe, is lower than potassium, K, in the activity series and cannot displace it from aqueous solutions.
Reaction 3 will occur since platinum, Pt, is lower than copper, Cu, in the activity series and thus can be displaced by copper from aqueous solutions.
Reaction 4 will occur since chromium, Cr, is higher than hydrogen, H, in the activity series and thus, can displace it from aqueous solutions.
You buy rice at 0.71 a pound one batch of fried rice requires 9 pounds of rice how much does the rice for one batch cost round to the nearest cent
After adding 20.0 mL of 5% NaOH solution into the remaining organic layer, followed by mixing and venting, the solution separated into two distinct layers. Match the following:
1. The top layer was the ______________ layer.
2. 9-fluorenone was most soluble in the ____________ layer.
3. Deprotonated chloroanilic acid was most soluble in the _____________ layer.
4. The bottom layer was the __________________ layer.
5. The organic layer was a ________________ colored solution.
6. The aqueous layer turned into a _____________ colored solution.
a. organic
b. aqueous
c. yellow
d. pink
Answer:
Explanation:
The objective of this experiment is to match the expected result with each of the propositions given after the experiment had been carried out.
1. The top layer was the organic layer. This is because all the organic compounds have lesser density than water except chloroform that will be formed when NaOH is added.
2. 9-fluorenone was most soluble in the organic layer. This is so as a result of its non-polar carbon structure.
3. Deprotonated chloroanilic acid was most soluble in the aqueous layer as a result of the formation of an electrovalent bond with water.
4. The bottom layer was the aqueous layer as a result of the huge amount of water density.
5. The organic layer was a yellow colored solution.
6. The aqueous layer turned into a pink colored solution.
. Calculate the pH of a solution made by dissolving 1.87 g of sodium caproate, NaC6H11O2, Kb =
7.58 x 10-10, in water and diluting to a total volume of 500.0 mL.
Answer:
Hindi ko po alam pero subukan ko pong sagutan yan
You place a pot of soup on the stove. As the soup warms you notice some areas where soup is rising up and
other areas where soup is sinking down.
1. Why do you think some of the soup is rising up?
Answer:
Convention
Explanation:
Answer:
Because the soup became warm and less dense, so it rose up.
Explanation:
Found on Course Hero is an American education technology website company based in Redwood City, California, which operates an online learning platform for students to access course-specific study resources contributed by a community of students and educators.
balanced or not balanced
2 H2 + 2 NO 2 H2O + N2
Answer: balanced
Explanation:
How many grams of iron (III) oxide are needed to produce 86.0 g of iron metal?
Answer: 122.9 g
Explanation: Fe2O3 mw = 160 of which 112 is Fe
to get 86 g Fe, 86*160/112 g oxide
Plz someone answer my question..
Answer:
Z = 1 - a/VRT
Explanation:
Note :
Compressibility Factor, Z = PV / RT
Vander waal forces at Lower pressure is represented by the expression :
V[P + a/V²] = RT
Aim is to move PV /RT =Z to one side of the equation.
Using change of subject :
opening the bracket :
PV + aV / V² = RT
PV + a/V = RT
Divide through by RT
PV/RT + a/VRT = RT/RT
PV/RT + a/VRT = 1
Recall:
PV /RT = Z
equation becomes :
Z + a/VRT = 1
Subtract a/VRT from both sides
Z + a/VRT - a/VRT = 1 - a/VRT
Z = 1 - a/VRT
The distance between the centers of the two oxygen atoms in an oxygen molecule is 1.21 x 10-8 cm. What is this distance in inches?
Answer:
[tex]d=4.75\times 10^{-9}\ \text{inches}[/tex]
Explanation:
Given that,
The distance between the centers of the two oxygen atoms in an oxygen molecule is [tex]1.21\times 10^{-8}\ cm[/tex].
We need to convert this distance in inches.
We know that,
1 cm = 0.393 inches
We can solve it as follows :
[tex]1.21\times 10^{-8}\ cm=0.393\times 1.21\times 10^{-8}\\\\=4.75\times 10^{-9}\ \text{inches}[/tex]
So, the distance between the centers of the two oxygen atoms is [tex]4.75\times 10^{-9}\ \text{inches}[/tex].
Naturally occurring silicon consists of three isotopes with the following isotopic masses and abundances. IsotopeIsotopic mass (u)Abundance (%) 28 Si 27.9769265327 92.2297 29 Si 28.97649472 4.6832 30 Si 29.97377022 3.0872 Calculate the average atomic mass of naturally occurring silicon to at least four significant figures.
Answer: The average atomic mass of naturally occurring silicon is 28.08
Explanation:
Mass of isotope Si-28 = 27.9769265327
% abundance of isotope Si-28 = 92.2297% = [tex]\frac{92.2297}{100}[/tex]
Mass of isotope Si-29 = 28.97649472
% abundance of isotope Si-29 = (4.6932)% = [tex]\frac{4.6832}{100}[/tex]
Mass of isotope Si-30 = 29.97377022
% abundance of isotope Si-30 = (3.0872)% = [tex]\frac{3.0872}{100}[/tex]
Formula used for average atomic mass of an element :
[tex]A=\sum[(27.9769265327\times \frac{92.2297}{100})+(28.97649472\times \frac{4.6832}{100})+(29.97377022\times \frac{3.0872}{100})][/tex]
[tex]A=28.08[/tex]
Therefore, the average atomic mass of naturally occurring silicon is 28.08
The photoelectric effect occurs when _____ are emitted from metal when the metal is struck by light of certain frequencies.
Answer:
electrons
Explanation:
The photoelectric effect occurs when electrons are emitted from metal when the metal is struck by light of certain frequencies.
Some of the applications of this effect include photomultipliers (which are a key component in spectroscopy instruments) and night vision devices.
Answer:
Electrons
Explanation:
Edge 2021
1. Fred is walking at 1.7 m/s, he sees a dollar and runs at 2.5 m/s in 1.5 seconds.
What is his acceleration?
Answer:
Acceleration is the rate of change of velocity. Usually, acceleration means the speed is changing, but not always. When an object moves in a circular path at a constant speed, it is still accelerating, because the direction of its velocity is changing.
Explanation:
It goes with velocity
Which of the following involves a reaction in which energy is absorbed?
O A. An instant cold pack
O B. A car's engine
C. A chemical hand-warmer
O D. A campfire
The reform reaction between steam and gaseous methane (CH4) produces "synthesis gas," a mixture of carbon monoxide gas and dihydrogen gas. Synthesis gas is one of the most widely used industrial chemicals, and is the major industrial source of hydrogen. Suppose a chemical engineer studying a new catalyst for the reform reaction finds that 924. liters per second of methane are consumed when the reaction is run at 261.°C and 0.96atm. Calculate the rate at which dihydrogen is being produced.
Answer:
The answer is "[tex]= 0.078 \ kg \ H_2[/tex]".
Explanation:
calculating the moles in [tex]CH_4 =\frac{PV}{RT}[/tex]
[tex]=\frac{(0.58 \ atm) \times (923 \ L) }{ (0.0821 \frac{L \cdot atm}{K \cdot mol})(232^{\circ} C +273)}\\\\=\frac{(535.34 \ atm \cdot \ L) }{ (0.0821 \frac{L \cdot atm}{K \cdot mol})(505)K}\\\\=\frac{(535.34 \ atm \cdot \ L) }{ (41.4605 \frac{L \cdot atm}{mol})}\\\\= 12.9 \ mol[/tex]
Eqution:
[tex]CH_4 +H_2O \to 3H_2+ CO \ (g)[/tex]
Calculating the amount of [tex]H_2[/tex] produced:
[tex]= 12.9 \ mol CH_4 \times \frac{3 \ mol \ H_2 }{1 \ mol \ CH_4}\times \frac{2.016 g H_2}{1 \ mol \ H_2}\\\\= 78 \ g \ H_2 \\\\= 0.078 \ kg \ H_2[/tex]
So, the amount of dihydrogen produced = [tex]0.078 \frac{kg}{s}[/tex]
number of balance electrons of a non ionized oxygen atom
A student obtained 1.57 g of product in a chemical reaction in the lab although she expected to produce 2.04 g of product. What was the percent yield of the experiment?
A. 23.1%
B. 43.4%
C. 56.5%
D. 77.0%
Answer:
D. 77.0%
Explanation:
% yield = actual yield/theoretical yield x 100%
% yield = 1.57 g / 2.04 g x 100%
% yield = 76.96 (round up)
A thermometer reads -111.1 °F. What is the temperature in °C?
this is an example of what process ?