Answer:
Substance at the beginning of a reaction- reactant
Substance at the end of a reaction- product
Number placed before a compound in a chemical equation- stoichiometric coefficient
Explanation:
In a reaction equation, the species written on the left hand side of the equation are called the reactants.
The reactants combine to form the species on the right hand side of the reaction equation called products.
The stoichiometric coefficient is a number written before the formula of a compound in the reaction equation.
What is a characteristic that can be observed or measured without changing the chemical makeup of a substance? *
a.chemical property
b.physical property
c.chemical change
d.physical change
What child do parents dislike the most
Oldest Child
Middle Child
Youngest Child
Answer:
Oldest
Explanation:
toxicity
Answer:
Oldest
toxicity
Explanation:
please help me will mark brainly
Global warming is mainly due to
CFC's
Ozone Holes
Nitric and sulfuric acids
Greenhouse gases
Answer:
Explanation:
Glaciers are melting, sea levels are rising, cloud forests are dying, and wildlife is scrambling to keep pace. It has become clear that humans have caused most of the past century's warming by releasing heat-trapping gases as we power our modern lives. Called greenhouse gases, their levels are higher now than at any time in the last 800,000 years.
We often call the result global warming, but it is causing a set of changes to the Earth's climate, or long-term weather patterns, that varies from place to place. While many people think of global warming and climate change as synonyms, scientists use “climate change” when describing the complex shifts now affecting our planet’s weather and climate systems—in part because some areas actually get cooler in the short term.
Climate change encompasses not only rising average temperatures but also extreme weather events, shifting wildlife populations and habitats, rising seas, and a range of other impacts. All of those changes are emerging as humans continue to add heat-trapping greenhouse gases to the atmosphere, changing the rhythms of climate that all living things have come to rely on.
What will we do—what can we do—to slow this human-caused warming? How will we cope with the changes we've already set into motion? While we struggle to figure it all out, the fate of the Earth as we know it—coasts, forests, farms, and snow-capped mountains—hangs in the balance.
Match the following parts of the earth with the correct definition: Definitions: 1. Solid, outer layer of the earth 2. Layer between the crust and the core 3. Semi-liquid region directly beneath the crust 4. Made of iron and nickel 5. The water covering the surface of the earth
Words: Mantle, Core, Crust, Hydrosphere, Asthenosphere
Answer:
1) crust
2)mantle
3) asthenosphere
4)core
5) hydrosphere
Explanation:
Hope this helps, Let me know if i am wrong( i dont think i am but, yeah...), OH! and GOOD LUCK! :D ;P.
Scientist looking for new substances in plants grind up the plants with methanol. This solvent dissolves many plant compounds. However, methanol is flammable and toxic (especially if the vapour is inhaled). Large crystals can be made to help scientists work out what the compounds are made of. Explain how you would make plant-compound crystals using methanol.
Answer:
See explanation
Explanation:
Crystals can be made from methanol by recrystallizing the plant extract from methanol.
The methanol/water system is heated rapidly using a hot plate and the plant extract dissolves in the heating solution until a clear solution is obtained.
The solution is now cooled rapidly. The interior of the flask used for the re crystallization may even by scratched to assist the quick formation of crystals. Large crystals of plant compounds may be obtained using this method. This process should be carried out in a fume hood because of the toxicity of methanol.
In the titration of acetic acid, CH3COOH, a 0.20 M solution of NaOH is used. A volume of 15.00 mL of CH3COOH solution is
titrated. If it takes a total of 24.55 mL of NaOH solution to reach the equivalence point, what is the molar concentration of the
CH3COOH solution?
Answer:
naci
Explanation:
The molar concentration of the CH₃COOH soluttion is 0.33 M
We'll begin by writing the balanced equation for the reaction. This is given below:
CH₃COOH + NaOH —>CH₃COONa + H₂O
From the balanced equation above,
The mole ratio of the acid, CH₃COOH (nA) = 1
The mole ratio of the base, NaOH (nB) = 1
From the question given above, the following data were obtained:
Volume of acid, CH₃COOH (Va) = 15 mL
Molarity of base, NaOH (Mb) = 0.2 M
Volume of base, NaOH (Vb) = 24.55 mL
Molarity of acid, CH₃COOH (Ma) =?MaVa / MbVb = nA/nB
(Ma × 15) / (0.2 × 24.55) = 1
(Ma × 15) / 4.91 = 1
Cross multiply
Ma × 15 = 4.91
Divide both side by 15
Ma = 4.91 / 15
Ma = 0.33 MTherefore, the molar concentration of the acid, CH₃COOH is 0.33 M
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1-Convert the following to moles:
1.5 X 10^23 atoms of Carbon
Answer:
0.249087
Explanation:
1.5 x 10^23 atoms x 1 mole / 6. 022 x 10^23 atoms
= 0.249087
In which option do all three particles have the same electronic configuration?
And the same number of neutrons? (7N , 8O , 9F ,10Ne , 12Mg)
(a) 15N3- 16O2- 19F-
(b) 18O2- 19F- 20Ne
(C) 19F- 20Ne 23Na+
(d) 22Ne 23Na 24Mg2+
b. ₈¹⁸O²⁻ , ₉¹⁹F⁻ , ₁₀²⁰Ne
Further explanationThe Atomic Number (Z) indicates the number of protons and electrons in an atom of an element.
Atomic number = number of protons = number of electrons ⇒ neutral number
Atomic mass is the sum of protons and neutrons
Atomic Number (Z) = Atomic mass (A) - Number of Neutrons
₈¹⁸O²⁻Atomic mass = 18
Atomic number = 8 , gain 2 electron ⇒ total 10 electrons
Configuration : 1s², 2s², 2p⁶ (10 electrons)
Neutrons : 18 - 8 = 10
₉¹⁹F⁻Atomic mass = 19
Atomic number = 9 , gain 1 electron ⇒ total 10 electrons
Configuration : 1s², 2s², 2p⁶ (10 electrons)
Neutrons : 19 - 9 = 10
₁₀²⁰NeAtomic mass = 20
Atomic number = 10
Configuration : 1s², 2s², 2p⁶ (10 electrons)
Neutrons : 20 - 10 = 10
15.
Which species contains 16 protons, 17 neutrons and 18 electrons?
a. 325
b. 3382-
d. 3592-
C. 345
N yogurt de 125 g muestra en su etiqueta el contenido de algunas de sus sustancias nutricionales:¿Cuál es la composición en tanto porciento en masa de cada una de las sustancias? Composición Sustancia Masa Proteínas 5,5 g Azúcares 5,0 g Sodio 0,06 g Potasio 0,15 g
Answer:
Sustancia Masa (g) Composición (% m/m)
Proteínas 5,5 4,4
Azúcares 5,0 4,0
Sodio 0,06 0,048
Potasio 0,15 0,12
Explanation:
Para calcular la composición porcentual en masa de las sustancias debemos usar la siguiente ecuación:
[tex] \%_{m/m} = \frac{m_{s}}{m_{sol}} \times 100 [/tex]
En donde:
[tex]m_{s}[/tex] es la masa de la sustancia
[tex]m_{sol}[/tex] es la masa del yogurt = 125 g
Para las proteínas:
[tex] \%_{m/m} = \frac{m_{s}}{m_{sol}} \times 100 = \frac{5,5 g}{125 g} \times 100 = 4,4 \% [/tex]
Para los azúcares:
[tex] \%_{m/m} = \frac{5,0 g}{125 g} \times 100 = 4,0 \% [/tex]
Para el sodio:
[tex] \%_{m/m} = \frac{0,06 g}{125 g} \times 100 = 0,048 \% [/tex]
Para el potasio:
[tex] \%_{m/m} = \frac{0,15 g}{125 g} \times 100 = 0,12 \% [/tex]
Espero que te sea de utilidad!
which atom in each pair has the larger atomic radius?
li or k
ca or ni
ga or b
o or c
cl or br
be or ba
si or s
fe or au
Answer:
1. Potassium, K.
2. Calcium, Ca.
3. Gallium, Ga.
4. Carbon, C.
5. Bromine, Br.
6. Barium, Ba.
7. Silicon, Si.
8. Gold, Au.
Explanation:
Atomic radius can be defined as a measure of the size (distance) of the atom of a chemical element such as hydrogen, oxygen, carbon, nitrogen etc, typically from the nucleus to the valence electrons. The atomic radius of a chemical element decreases across the periodic table, typically from alkali metals (group one elements such as hydrogen, lithium and sodium) to noble gases (group eight elements such as argon, helium and neon). Also, the atomic radius of a chemical element increases down each group of the periodic table, typically from top to bottom (column).
Additionally, the unit of measurement of the atomic radius of chemical elements is picometers (1 pm = 10 - 12 m).
1. Li or K: the atomic radius of lithium is 167 pm while that of potassium is 243 pm.
2. Ca or Ni: the atomic radius of calcium is 194 pm while that of nickel is 149 pm.
3. Ga or B: the atomic radius of gallium is 136 pm while that of boron is 87 pm.
4. O or C: the atomic radius of oxygen is 48 pm while that of carbon is 67 pm.
5. Cl or Br: the atomic radius of chlorine is 79 pm while that of bromine is 94 pm.
6. Be or Ba: the atomic radius of berryllium is 112 pm while that of barium is 253 pm.
7. Si or S: the atomic radius of silicon is 111 pm while that of sulphur is 88 pm.
8. Fe or Au: the atomic radius of iron is 156 pm while that of gold is 174 pm.
The atoms in each pair which has the larger atomic radius is;
Potassium, K.Calcium, Ca.Gallium, Ga.Carbon, C.Bromine, Br.Barium, Ba.Silicon, Si.Gold, Au.Definition:
Atomic radius is simply the distance from the centre of the nucleus to the outermost shell containing electrons.
In other words, the atomic radius is the distance from the center of the nucleus to the point up to which the electron cloud density is maximum.
Trend:
The atomic radius of atoms generally decreases from left to right across a period. The atomic radius of atoms generally increases from top to bottom within a group.
It is on this basis that atoms with the larger atomic radius are determined
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(2 words) if compose means to put together then decompose means to what? 9 letters!
compare and contrast the similarities and differences between passive and active transport
which of these processes are chemical reaction
Answer:
I don't think u finished the question -
Which choices are layers of the atmosphere? Select the five correct answers. Mesosphere Danosphere Croposphere Stratosphere Thermosphere Exosphere Meteorosphere Troposphere
Answer:
Mesosphere
Stratosphere
Thermosphere
Troposphere
Exosphere
Explanation:
The exosphere refers to the farthest region of the atmosphere that gradually fades into space.
The troposphere is the lowest layer of atmosphere. It is the layer where weather changes occur.
The thermosphere is right above the mesosphere but just below the exosphere. It is the layer where photoionization/photodissociation of molecules occurs thereby creating ions. This largely owes to interaction of molecules in this layer with ultraviolet radiation.
The stratosphere is composed of gases. Prominent among them is ozone which serves as a blanket against the sun's ionizing radiation.
The mesosphere lies above the stratosphere but just below the thermosphere. Temperature decreases steadily with height in the mesosphere.
The 5 layers of the atmosphere are the troposphere, stratosphere, mesosphere, thermosphere, and exosphere.
The atmosphere has been consisted of the 5 layers that protect the earth. The layers have been present at the height that and each layer has consisted of different constituents.
The layers of the atmosphere can be described as:
Exosphere: It has been the layer farthest to the earth and has been consisted of space.Thermosphere: It has been layer followed by the exosphere. The layer has been consisted of satellites and rockets.Mesosphere: The layer has been at the height of 50-90 km and has been consisted of meteors, stars, and meteorically rockets.Stratosphere: The layer has been at the 12-50 km height and has been consisted of radio-sounds and waves.Troposphere: The innermost layer of the atmosphere. It has consisted of clouds, planes, and balloons.The 5 layers of the atmosphere are the troposphere, stratosphere, mesosphere, thermosphere, and exosphere.
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Sort the characteristics based on whether they describe a dog, a computer, or both.
has internal
organization
has living
cells
uses energy
produces
offspring
lacks genetic
material
Answer:
both have internal organization dog only has living cells both use energy dogs only produce offspring computers only lack genetic material
hi pls help me I don't get it
Answer:
It's most probably
A non metal
Please help due in 5 min. I need this to be done or my grade will drop from a 96 to a 32.
Calculate the energy and frequency of red light having a wavelength of 6.55 x 10^-5 cm.
Answer:
E = 3.035× 10-¹⁹J = 1.9eV
f = 4.58 × 10¹⁴Hz
Explanation:
wavelength = 6.55 × 10-⁷m
c = 3 × 10⁸m/s
f = ?
E = ?
a) f = c/wavelength
f = 3 × 10⁸/6.55 × 10-⁷
f = 4.58 × 10¹⁴Hz
b) E = hc/wavelength
E = 6.626×10-³⁴ × 3 × 10⁸/ 6.55 × 10-⁷
E = 3.035 × 10-¹⁹J
1ev = 1.6 × 10-¹⁹J
Therefore E = 3.035/1.6 = 1.9eV
Explanation:
speed of light = wavelength * frequency
frequency =speed of light/wavelength
Let frequency = F
Speed of light = 3.0 *10^8
wavelength = 6.55 * 10^-5 cm = 6.55 * 10^-7m
Therefore F= 3.0 *10^8m/s *6.55 * 10^-7m
F = 196.5Hz
Energy = Planck's constant * frequency
Let energy be E
Planck's constant = 6.63 * 10^-34Joule/ seconds
E = 6.63 * 10^-34 * 196.5Hz
E=1.3027 * 10^-31 J
lonic compounds can conduct electricity in
Answer:
Ionic compounds conduct electricity when molten (liquid) or in aqueous solution (dissolved in water), because their ions are free to move from place to place. Ionic compounds cannot conduct electricity when solid, as their ions are held in fixed positions and cannot move
Explanation:
How does the amount of fertilizer affect how many potatoes a plant produces?
Answer:
Excess fertilizer alters the soil by creating too high of a salt concentration, and this can hurt beneficial soil microorganisms. Over- fertilization can lead to sudden plant growth with an insufficient root system to supply adequate water and nutrients to the plant
Explanation:
Which ocean borders Africa on the western coast?
pls answer for 20 coiins
Answer:
indian ocean
Explanation:
State joule thomson effect
Answer:
In thermodynamics, the Joule–Thomson effect describes the temperature change of a real gas or liquid when it is forced through a valve or porous plug while keeping it insulated so that no heat is exchanged with the environment. This procedure is called a throttling process or Joule–Thomson process
5 grams of KClO3 is dissolved in 100 g of water at 30 °C. How
many more grams of Kcloz Should be added in order to create a
saturated solution?
A 5 grams
B
10 grams
С
15 grams
D
1 gram
Answer:
15 grams
Explanation:
Which of the following is a inert gas?
oxygen
chlorine
nitrogen
aragon
Answer:
argon is an inert gas
Explanation:
an inert gas is when a chemical helium, xenon, neon, krypton, radon are also inert gases
A vessel of capacity 400 cc filled with chlorine under 80 cm is connected by a narrow tube and stopcock with another vessel of capacity 250 cc filled with nitrogen under 100 cm. what will be the pressure when the stopcock is opened?
Answer:
The pressure when the stopcock is opened is opened is 87.783 cm
Explanation:
The given parameters of the question are;
The volume of the vessel of chlorine = 400 cc
The pressure of the vessel of chlorine = 80 cm
The volume of the vessel of chlorine = 250 cc
The pressure of the vessel of chlorine = 100 cm
Daltons law of Partial Pressures states that the total pressure exerted by a volume of a mixture of gases is equal to the partial pressures exerted by the individual gases in the mixture with respect to the given volume
Therefore;
The total volume of the mixture = 400 cc + 250 cc = 650 cc
The partial pressure exerted by the chlorine gas in the total volume is given by Boyles law as follows;
P₁·V₁ = P₂·V₂
P₂ = P₁·V₁/V₂
Where;
P₁ = 80 cm = The pressure in volume V₁ = 400 cc
P₂ₓ = The partial pressure of chlorine in volume V₂ = 650 cc
Substituting, we have;
P₂ₓ = 80 × 400/650 ≈ 49.321 cm
Similarly, the partial pressure exerted by the nitrogen gas in the total volume is given by Boyles Law as follows;
P₂ₐ = P₁·V₁/V₂
Where;
P₁ = 100 cm = The pressure in volume V₁ = 250 cc
P₂ₐ = The partial pressure of nitrogen in volume V₂ = 650 cc
Substituting, we have;
P₂ₐ = 100× 250/650 ≈ 38.462 cm
The pressure of the combined gas, P, when the stopcock is opened is opened is given by Dalstons Law of partial pressure as P = P₂ₐ + P₂ₓ
Therefore, the pressure, P when the stopcock is opened is opened = 49.321 cm + 38.462 cm = 87.783 cm
What element is represented by each electron
configuration?
A. 1s 2s22p5
B. [Ar]4s
C. [Xe]6s24f
D. [Kr]5s4d105p+
E. [Rn]7s25f13
F. 1s 2s 2p 3s 3p 4s3d104p
Answer:
F.1s 2s 2p 3s 3p 4s3d104p
The element in the first configuration is F and the element in the second option is calcium Ca. The configuration in option c is of cerium Ce and it is cadmium in option D. The configuration in E is mendelevium and F is zinc.
What is electronic configuration?An electronic configuration represents the filling of electrons in various energy level. Electrons fill from the lowest energy levels to the highest energy level.
The first configuration have a total of 9 electrons. The 9th element is fluorine. The second configuration given is of 20 electrons. That is 18 electrons of argon plus 2 electrons in 4s. The 20th element is calcium.
The third configuration have 58 electrons and the element is cerium Ce. The configuration given in option D is of cadmium with 48 electrons and that in option E is mendelevium with 101 electrons.
In the last option, the configuration contain a total of 30 electrons. 3o th element in periodic table is zinc, Zn.
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omg can somebody please help me with these 2 questions
Answer: Q4=1 Q5=2
Explanation:
Best of luck.
Answer:
4. '4' "pathogens can interfere with normal life functions."
5. '2' "synthesizing antibodies that mark these organisms to be destroyed."
Explanation:
The white Dwarfs are a group of stars that are-
A)Extremely bright and hot
B)Low in brightness but are average to high in temperature
C)Average in brightness but high in temperature
D)Average in brightness and average in temperature
Answer: A
Explanation:
The white Dwarfs are a group of stars that are extremely bright and hot. Hence option A is correct.
What are stars?Stars are defined as any large gaseous heavenly body that emits light as a result of its own internal energy sources. Stars are celestial bodies that generate their own energy through the fusing of gases. They resemble bright orbs that burn gas and produce energy. Our solar system's star, the Sun, generates energy through the fusion reaction in which helium transforms into hydrogen.
When a white dwarf first forms, it is extremely hot, but because it has no energy source, it will gradually cool as it emits its energy into space. This implies that the color temperature of its radiation, which is initially high, will gradually decrease and turn red. After using up all of their nuclear fuel, stars like the Sun become white dwarfs.
Thus, the white Dwarfs are a group of stars that are extremely bright and hot. Hence option A is correct.
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Determine the number of protons, neutrons, and electrons for a neutral potassium-41 isotope.