Answer:
21.25
Explanation:
The element fluorine has an atomic number of
a. 10
b. 9
c. 19
d. 28
Answer:
B.9
Explanation:
consider an atom that has an electron in an exicted state . the electron falls to a lower energy level . what effects does that have on the electron ?
Answer:
Each time an excited helium atom falls back from an excited state to its ground state or to a lower energy state, it emits a photon of radiation that shows up as this specific line-emission spectrum.
Explanation:
What is the reactant(s) in the chemical equation below?
Answer:
C. 3CO(g) + Fe2O3(s)
Explanation:
The substance(s) to the hath left of the arrow in a chemical equation art hath called reactants. A reactant is a substance yond is presenteth at the starteth of a chemical reaction. The substance(s) to the right of the arrow art hath called products. A product is a substance yond is presenteth at the endeth of a chemical reaction
So in this example, 3CO(g) + Fe2O3(s) art the reactants.
The 2Fe(S) + 3CO2(G) art the products.
Desire I holp! Has't a most wondrous day!
Hope I helped! Have a great day!
Analyzing the results of your experiment includes
How many grams of carbon dioxide are produced by the combustion of 2.5 moles of ethane gas, C 2 H 6 at standard conditions?
2 C 2 H 6 (g)+7 O 2 (g) 4 CO 2 (g)+6 H 2 O (g)
Answer:
220g
Explanation:
The reaction equation is given as:
2C₂H₆ + 7O₂ → 4CO₂ + 6H₂O
Number of moles of ethane gas = 2.5moles
To find the mass of CO₂ produced, we need to know the number of moles of the compound produced;
2 mole of ethane gas produced 4 moles of CO₂
2.5 moles of ethane gas will produce [tex]\frac{2.5 x 4}{2}[/tex] = 5mole of CO₂
So;
Mass of CO₂ = number of moles x molar mass
Molar mass of CO₂ = 12 + 2(16) = 44g/mol
Mass of CO₂ = 5 x 44 = 220g
A student performed an investigation to determine if the rate of photosynthesis in elodea is affected by a higher than normal concentration of carbon dioxide gas in the water in which the plant is growing. After increasing the concentration of carbon dioxide in water, the student illuminated the plant with a light and collected the bubbles of oxygen gas that were given off from the cut end of the submerged plant. In this investigation, what would be the best indicator of the rate of photosynthesis? a a change in the color of the plant b an increase in the length of the elodea plant over a period of 12 hours c the amount of light that is transmitted through the water d the amount of oxygen collected over a period of 12 hours
Answer:
D. the amount of oxygen collected over a period of 12 hours
Explanation:
Photosynthesis is a metabolic reaction performed by the cells of plant. In this reaction, light is used as an energy source to combine carbon dioxide (CO2) and water (H2O) to produce glucose and oxygen gas (O2) as products. In every chemical reaction including photosynthesis, an increase in concentration of reactants will increase the rate of the reaction, which is evident in the amount of products formed.
According to this question where a student is performing an investigation to determine the relationship between a higher than normal concentration of carbon dioxide gas and the rate of photosynthesis. After increasing the concentration of carbon dioxide in water, the student illuminated the plant with a light and collected the bubbles of oxygen gas that were given off from the cut end of the submerged plant.
Based on the above explanation, the best indicator of the rate of photosynthesis in this investigation will be THE AMOUNT OF OXYGEN COLLECTED OVER A PERIOD OF 12 HOURS.
Which kind of energy change occurs when a candle is burning
Answer:
2 Answers. This would be chemical energy that is converted to heat. The heat from the wick melts the wax which gets absorbed in the wick and then gets burnt (which is really oxidation) to produce heat energy as well as light energy.
Explanation:
A candle must undergo a chemical reaction in order to burn, producing heat and light. As a result, energy changes from chemical energy to heat and light energy. As a result, as a candle burns, chemical energy is transformed into heat and light energy.
What is chemical energy ?Chemical energy is the energy that is released when chemical substances engage in a chemical reaction and change into other substances. Batteries, food, and gasoline energy are some instances of chemical energy storage media.
A type of potential energy associated with the structural organization of atoms or molecules is known as chemical potential energy. Chemical connections or interactions between molecules may have led to this configuration.
They are broken down into simpler molecules, such as glucose and amino acids, which are then either reassembled and stored in various forms, such as glycogen, or consumed as energy. Chemical energy in food is essential for giving our bodies the fuel they require to keep us alive and active.
Thus, energy changes from chemical energy to heat and light energy.
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1. What's the difference between a proton and a positively charged hydrogen ion?
Answer:
Theoretically not directly describing, .Atoms vs Ions an ion is an electrically charged particle produced by either removing electrons from a neutral atom to give a positive ion or adding electrons to a neutral atom to give a negative ion. When an ion is formed, the number of protons does not change.
Neutral atoms can be turned into positively charged ions by removing one or more electrons. A neutral sodium atom, for example, contains 11 protons and 11 electrons. By removing an electron from this atom we get a positively charged Na+ ion that has a net charge of +1.
Atoms that gain extra electrons become negatively charged. A neutral chlorine atom, for example, contains 17 protons and 17 electrons. By adding one more electron we get a negatively charged Cl- ion with a net charge of -1.
The gain or loss of electrons by an atom to form negative or positive ions has an enormous impact on the chemical and physical properties of the atom. Sodium metal, for example, which consists of neutral sodium atoms, bursts into flame when it comes in contact with water. Neutral chlorine atoms instantly combine to form Cl2 molecules, which are so reactive that entire communities are evacuated when trains carrying chlorine gas derail. Positively charged Na+ and negatively charged Cl- ions are so unreactive that we can safely take them into our bodies whenever we salt our food.
Explanation:
mark brainlist
How can you ensure the chemical reaction produces the right amount of heat in a hot pack without hurting you?
Answer:
Heat packs that contain iron and water packets: Exposing the solution to air results in the oxidation of the iron (creates rust). The oxidation of the iron is an exothermic process. Heat packs that contain supersaturated sodium acetate: These are reusable, the packs are boiled to dissolve sodium acetate.
Explanation:Thanks for asking question
30g of solute is dissolved in 100g of water. Calculate its % (m/m) concentration.
Answer:
23%
Explanation:
Daffodil is ordering office supplies for her company. When she tries to order pencils, she finds that pencils are sold by the gross, which is equal to 144 pencils. Daffodil checks how many pencils her company uses in a year, and decides to order 5 gross of pencils. How many pencils will she receive? Remember to include units (full word, plural, WATCH YOUR SPELLING) as they are worth half of this question.
Answer:
720 pencils
Explanation:
The parameter given are;
The unit quantity by which the pencils are sold = 1 gross
The number of pencils Daffodil orders = 5 gross of pencils
One gross is a quantity equal to twelve dozens
Therefore, we can write;
1 gross = 12 × 12 = 144
From which we have;
5 gross = 5 × 144 = 720
Which gives;
For the 5 gross of pencils Daffodil orders, she receives 720 pencils
What do the red arrows represent
Answer:
There are three forces acting on the skateboard. One of these forces is the weight of the rider. Another is the force of gravity on the board itself. The third is the force of the ground pushing up on the skateboard.
ILL GIVE YOU BRAIN LIEST IF YOU KNOW THE ANSWERS
Answer:B & C
tell me if im wrong
Answer:
Q 3 c it will reduce rate of photosynthesis in plants that live in the bottom of the lake
Q4 d the atom are in same group
This is right answer because these two elements are Lithium and neon Lithium is present in first group and Neon in last or group 18
Explanation:
Electrons are arranged in orbits called energy levels. The Gizmo shows all of the
first two energy levels but only part of the third energy level.
A. How many electrons can fit in the first energy level?
B. How many electrons can fit in the second energy level?
C. How many electrons fit in the part of the third energy level shown?
Answer:
A is 2, B is 8, and C is 18
Explanation:
I did the Gizmos
The two, eight, and eighteen electrons can be filled in the first, second, and third energy levels respectively.
What are the energy levels?The electrons revolve in different orbits are known as energy levels or stationary states. These energy levels are numbered as n = 1, 2, 3…… These values are also known as the principal quantum numbers.
The first energy level is also known as 'K' shell or level. The second energy level is called 'L' shell, the third energy level is 'M' shell, and so on.
The electrons present in the K shell contain the least energy whereas the levels contain more energy that is far from the nucleus.
The first energy level (n = 1) can have maximum two electrons in it. The second energy level ( n= 2) can have maximum eight electrons and the third energy level can fill maximum eighteen electrons in it.
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The four planets closest to the sun that are mostly made of rock and metal
Answer:
Mercury, Venus, Earth and Mars.
Explanation:
Explain why the answer is correct and why the others aren’t.
Pleaseeee
Answer:
Buffalo and Watertown.
Explanation:
This is correct as the Interior lowlands are located ib the US. These are correct as the others are in the US but aren't located anywhere near the Interior Lowlands.
The following diagram shows the bonds that make up potassium acetate.
Answer:
6
Explanation:
ye
What would Thomson's model and Rutherford's model of the atom have in common?
Answer:
Thomson's plum pudding model of the atom had negatively-charged electrons embedded within a positively-charged "soup." Rutherford's gold foil experiment showed that the atom is mostly empty space with a tiny, dense, positively-charged nucleus. Based on these results, Rutherford proposed the nuclear model of the atom.
Explanation:
Answer:
From another website, “Thomson's plum pudding model of the atom had negatively-charged electrons embedded within a positively-charged "soup." Rutherford's gold foil experiment showed that the atom is mostly empty space with a tiny, dense, positively-charged nucleus. Based on these results, Rutherford proposed the nuclear model of the atom.”
Explanation:
How many seconds in 4.3 years?
In the given question, 136293840 seconds are present in 4.3 years.
A second is a unit of time that is equal to 1/60th of a minute and is used to measure short periods of time.
To convert 4.3 years to seconds, we can use the following conversion factors:
1 year = 365.25 days (accounting for leap years)
1 day = 24 hours
1 hour = 60 minutes
1 minute = 60 seconds
So, we can start by multiplying the number of years by the number of days per year:
4.3 years [tex]\times[/tex] 365.25 days/year = 1577.475 days
Next, we can multiply the number of days by the number of hours per day:
1577.475 days [tex]\times[/tex] 24 hours/day = 37859.4 hours
Then, we can multiply the number of hours by the number of minutes per hour:
37859.4 hours [tex]\times[/tex] 60 minutes/hour = 2271564 minutes
Finally, we can multiply the number of minutes by the number of seconds per minute to get the total number of seconds:
2271564 minutes [tex]\times[/tex] 60 seconds/minute = 136293840 seconds
Therefore, in 4.3 years there are approximately 136293840 seconds.
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Try to balance the 5 attached equations.
Answer:
1)2kclo3=2kcl+3o2
2)2NaCl+F2=2NaF+cl2
3)Pb(OH)2+2HCl=2H2O+PbCl2
4)2Albr3+3k2so4=6kbr+al2(so4)3
5)CH4+2O2=CO2+2H2O
Why do scientist use the scientific method
Answer:
B
Explanation:
scientists always look for evidence
Answer:
Yea its B
Explanation: The person above me legit toke the answer out of my mouth
What is a disadvantage of geothermal energy
Answer:
it runs the risk of triggering earthquakes. releases harmful gases
2. Convert 120.02g of FrBiz to moles
a. 0.19 moles
b. 5.34 moles
c. 76,932.82 moles
Answer:
PRACTICE MULTIPLE CHOICE QUESTIONS FROM UNIT 10
1.) A cylinder is filled with 2.00 moles of nitrogen, 3.00 moles of argon, and 5.00 moles of helium. If
the gas mixture is at STP, what is the partial pressure of the argon?
(A) 152 torr (B) 228 torr (C) 380. torr (D) 760. torr
2.) Compared to the average kinetic energy of 1 mole of water at 0 oC, the average kinetic energy
of 1 mole of water at 298 K is
(A) the same, and the number of molecules is the same
(B) the same, but the number of molecules is greater
(C) greater, and the number of molecules is greater
(D) greater, but the number of molecules is the same
3.) If the pressure on a given mass of gas in a closed system is increased and the temperature
remains constant, the volume of the gas will
(A) decrease (B) increase (C) remain the same
4.) Which gas has approximately the same density as C2H6 at STP?
(A) NO (B) NH3 (C) H2S (D) SO2
5.) At a temperature of 273 K, a 400. milliliter gas sample has a pressure of 760. millimeters of
mercury. If the pressure is changed to 380. millimeters of mercury, at which temperature will
this gas sample have a volume of 551 milliliters?
(A) 100 K (B) 188 K (C) 273 K (D) 546 K
Get the answers to these questions
Back to the Unit 10 Old Tests Pag
this is just to make sure but plz help
What coefficient will balance the equation that is shown?
Al +_ HCI-H2 + ALCI,
Balanced equation :
2Al +6HCI⇒ 3H₂ + 2AlCI₃
Further explanationGiven
Reaction (unbalanced)
Al +HCI⇒ H₂ + ALCI₃
Required
Balanced equation
Solution
Give a coefficient
aAl +bHCI⇒ cH₂ + AlCI₃
Al, left = a, right=1⇒a= 1
Cl, left = b, right=3⇒b=3
H, left = b, right=2c⇒b=2c⇒3=2c⇒c=3/2
The equation becomes :
Al +3HCI⇒ 3/2H₂ + AlCI₃ x 2
2Al +6HCI⇒ 3H₂ + 2AlCI₃
How much energy is required to melt 2 kg of copper? Use the table below and
this equation: Q = mLfusion
A. 125.6 kJ
B. 9460 kJ
C. 414 kJ
D. 4730 kJ
Answer:
C. 414 kJ
Explanation:
Given parameters:
Mass of copper = 2kg
Unknown:
Amount of energy required to melt the copper = ?
Solution:
To solve this problem, we use:
Q = m L
m is the mass
L is the latent heat of fusion of copper = 207kJ/kg
So;
Q = 2 x 207 = 414kJ
The law of conservation of momentum states that if objects exert forces only on each other, their total momentum is ____________. Group of answer choices
Answer:
Conserved.
Explanation:
Momentum can be defined as the multiplication (product) of the mass possessed by an object and its velocity. Momentum is considered to be a vector quantity because it has both magnitude and direction.
Mathematically, momentum is given by the formula;
[tex] Momentum = Mass * Velocity [/tex]
The law of conservation of momentum states that the total linear momentum of any closed system would always remain constant with respect to time.
This ultimately implies that, the law of conservation of momentum states that if objects exert forces only on each other, their total momentum is conserved.
Density is defined by the equation d = m/v. Calculate the density of the wooden block, the rock, and the water by dividing the mass of each object by its volume.
Answer:
Density, d = 8.92 g/mL
Explanation:
Let mass of the wooden block, m = 46.83 g
The volume of the object, V = 5.25 mL
We need to find the density of the wooden block. The density of an object is given by its mass per unit volume.
density = mass/volume
[tex]d=\dfrac{46.83\ g}{5.25\ mL}\\\\=8.92\ g/mL[/tex]
So, the density of the wooden block is 8.92 g/mL.
Answer:
0.495 g/cm3
Explanation:
The reaction of Pb+4 and O-2 produces the compound of
a
Pb2O2
b
PbO
c
Pb2O
d
PbO2
Answer:
Pb₂O₄
Explanation:
The given species are:
Pb⁴⁺ O²⁻
Now, to solve this problem, we use the combining powers which corresponds to the number of electrons usually lost or gained or shared by atoms during the course of a chemical combination.
Pb⁴⁺ O²⁻
Combining power 4 2
Exchange of valencies 2 4
Now the molecular formula is Pb₂O₄
What is the frequency of light with a wavelength of 3.2 x 10^-16 m?
Answer:
f = 0.94 ×10²⁴ Hz
Explanation:
Given data:
Frequency of light = ?
Wavelength of light = 3.2 ×10⁻¹⁶ m
Solution:
Formula:
Speed of light = wavelength × frequency
c = λ × f
c = speed of wave = 3×10⁸ m/s
by putting values,
3×10⁸ m/s = f × 3.2 ×10⁻¹⁶ m
f = 3×10⁸ m/s / 3.2 ×10⁻¹⁶ m
f = 0.94 ×10²⁴ s⁻¹
f = 0.94 ×10²⁴ Hz (Hz = s⁻¹)