Answer:
Cygnus X-1 21 is the heaviest stellar hole to be discovered. Cygnus X-1 21 weighs 21 times as the sun's mass. Scientists previously assumed wrong, it is around 1.5 times heavier then the last estimate. Cygnus X-1 21 was discovered by scientists using VLBA (Very Long Baseline Array.) This was discovered without gravitational waves which is usually used in science.
The network is 10 radio dishes and ranges to the United States, from Hawaii to the Virgin Islands. VLBA was responsible for tracking radio-bright jets of material flowing out of Cygnus X-1’s black hole for six days straight. Cygnus X-1 is around 7,200 light-years from Earth, which contradicts the last estimate of 6,000. The measurement for this new discovery gives astronomers a tough challenge in their understanding of black holes. Theres more to come in science with each discovery made.
Explanation:
is this good?
Which of the following is true about the efficiency of energy transfer in an ecosystem?
a The more energy the organism requires, the more efficient the energy transfer.
b. All energy transfers have the same efficiencies.
C. The less energy the organism requires, the more efficient the energy transfer.
d. The most efficient energy transfers are in large, warm-blooded animals.
Please select the best answer from the choices provided
A
B
ОООО
C
D
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Answer:
C. The less energy the organism requires, the more efficient the energy transfer.
Answer:
C
Explanation:
Trust the process
Edge 2021
What is a solvent ?
Answer:
A solvent is a substance that dissolves a solute, resulting in a solution. A solvent is usually a liquid but can also be a solid, a gas, or a supercritical fluid.
Explanation:
what is full from of DTP
Answer:
Hellloooo
ur answer is
Desktop Publishing.
Explanation:
thanks hope it helps
A student dissolves of sodium hydroxide in of water in a well-insulated open cup. He then observes the temperature of the water rise from to over the course of minutes. Use this data, and any information you need from the ALEKS Data resource, to answer the questions below about this reaction: ()()() You can make any reasonable assumptions about the physical properties of the solution. Be sure answers you calculate using measured data are rounded to the correct number of significant digits. Note for advanced students: it's possible the student did not do the experiment carefully, and the values you calculate may not be the same as the known and published values for this reaction.
Is this reaction exothermic, endothermic, or neither?
a. exothermic
b. endothermic
c. neither
Answer: a. exothermic
Explanation:
An Endothermic reaction is a type of chemical reaction in which energy is absorbed from the surrounding. The temperature of the surrounding decreases.
An Exothermic reaction is a type of of chemical reaction in which energy is released into the surrounding. The temperature of the surrounding increases.
When sodium hydroxide is dissolved in water, the temperature of water rise which means the heat has been released during dissolution of sodium hydroxide, thus the reaction is exothermic.
For a particular reaction at 135.4 °C, Δ=−775.41 kJ/mol, and Δ=817.91 J/(mol⋅K).
Calculate ΔG for this reaction at 12.7 °C.
Δ=
Answer:
[tex]-675.053\ \text{kJ/mol}[/tex]
Explanation:
[tex]\Delta G[/tex] = Gibbs free energy = [tex]-775.41\ \text{kJ/mol}[/tex]
[tex]\Delta S[/tex] = Change in entropy = [tex]817.91\ \text{J/mol K}=0.81791\ \text{kJ/mol K}[/tex]
[tex]T[/tex] = Temperature = [tex]135.4^{\circ}\text{C}=408.55\ \text{K}[/tex]
[tex]\Delta H[/tex] = Change in enthalpy
Gibbs free energy is given by
[tex]\Delta G=\Delta H-T\Delta S\\\Rightarrow \Delta H=\Delta G+T\Delta S\\\Rightarrow \Delta H=-775.41+408.55\times 0.81791\\\Rightarrow \Delta H=-441.253\ \text{kJ/mol}[/tex]
[tex]T=12.7^{\circ}\text{C}=285.85\ \text{K}[/tex]
[tex]\Delta G=\Delta H-T\Delta S\\\Rightarrow \Delta G=-441.253-285.85\times 0.81791\\\Rightarrow \Delta G=-675.053\ \text{kJ/mol}[/tex]
The required Gibbs free energy is [tex]-675.053\ \text{kJ/mol}[/tex].
Different measurements are expressed in different units. Choose the correct Sl units for the following types of measurement 3 The SI units for measuring the velocity of the car: The SI units for measuring the acceleration of the car: The SI units for measuring force: The SI units for measuring mass: <
Answer:
The SI base units of length, mass, and time are the meter (m), kilogram (kg), and second (s), respectively. SI units are a metric system of units, meaning values can be calculated by factors of 10. Metric prefixes may be used with metric units to scale the base units to sizes appropriate for almost any application
Answer: 1. Meters per second
2.meters per second squared
3.newtons
4. Kilo
Explanation:
How many molecules of CO2 are present in 0.6642 moles of CO2?
Answer:
1* 6.022*10^23=6.022*10^23 molecules of CO2 are present.
What does the phrase gravitational pull mean as it is used in the text?
Because meteors are so small, they often get pulled into planetary orbits, while asteroids and comets are large enough that they stay within the gravitational pull of the sun.
1. A force that pushes one thing away from another
2. Something that makes an object stay on the ground
3. Something that pulls an object strongly downward
4. The force of one thing pulling another thing closer
85% of what number is 17? EXPLAIN
Answer:
85% of 20 is 17
Explanation:
You can multiply 85% and 20 or subtract 85% from 20.
Hydrogen gas + chlorine gas yields hydrogen chloride
Answer:
[tex]H_{2} + Cl_{2} --> 2HCl[/tex]
Explanation:
Hydrogen and chlorine are both diatomic, which means they occur in molecular pairs as gases. This means you will have two atoms of each on the left in the reactants, so you will need to add a coefficient of 2 to have 2 atoms of each on the right in the products.
Jeff wants to record the diameter of a long, thin wire using an instrument. Which of the following instruments should be use? A Altimeter B Microscope c Measuring scale D.Micrometer
Answer:
D
Explanation:
How many moles of Na are in 42g of Na?
Answer:
n=m/M, so
Explanation:
Molar mass of Na is 22,9... so rounded to 23
n=42g/23g/mol
=1,826mol
WILL GIVE THE BRAIN THING-
Complete the following single replacement reaction.
Al(s) + HNO3(aq)
What are the products before balancing
Answer:
The products are Al(NO₃)₃(aq) and H₂(g).
Al(s) + 3 HNO₃(aq) ⇒ Al(NO₃)₃(aq) + 1.5 H₂(g)
Explanation:
Let's consider the reaction between aluminum and nitric acid. This is a single replacement reaction, in which Al replaces H in HNO₃ to form aluminum nitrate. The unbalanced reaction is:
Al(s) + HNO₃(aq) ⇒ Al(NO₃)₃(aq) + H₂(g)
We start balancing N atoms by multiplying HNO₃ by 3.
Al(s) + 3 HNO₃(aq) ⇒ Al(NO₃)₃(aq) + H₂(g)
Finally, we get the balanced equation multiplying H₂ by 1.5.
Al(s) + 3 HNO₃(aq) ⇒ Al(NO₃)₃(aq) + 1.5 H₂(g)
what is the double bond of XeF4
15 15. Which two elements will form a covalent bond?
a. K & C c. Na & Ar
b. Ag & O d. C & Br
Answer:
K and Cl
Explanation:
Which of these metals will displace Iron from Iron Oxide ?
-Copper
-Magnesium
-Silver
-Tin
Answer:
Magnesium
Explanation:
Magnesium is above iron in the reactivity series, which means that Mg can take oxygen from iron as it is a more reactive metal.
What happens inside a can of spoiled food as gas is produced?
A. The pressure decreases.
B. The temperature increases.
C. The volume decreases.
D. The pressure increases.
Answer:D the pressure increases
Explanation:
Answer: D
Explanation:
the pressure increases
which energy transformation took place?
Answer:
C
Explanation:
The battery is chemical energy. When it is used in the flashlight, it produces light and thermal energy
PLZ MARK BRAINLIEST :)
how many atoms of N are in 5.6g of N?
Answer:
ᵐʸ friend ʰᵉʳᵉ ʲᵘˢᵗⁱⁿ ʰᵉˢ already taken ᵃⁿᵈ hes ᶜʳᵃᶜᵏᵉᵈ ᵃᵗ ᶠᵒʳᵗⁿⁱᵗᵉ my guy Uhhh
Explanation:
On a scale of 1️⃣ to , you’re a 9️⃣. I’m the 1️⃣ you need.
A gas occupies a volume of 140 mL at 35.0°C and 697 mm Hg. What is the volume of the gas at STP?
Answer:
113.80 mL
Explanation:
Given that:
Volume [tex]V_1 = 140 mL[/tex]
Temperature [tex]T_1 = 35.0^0C[/tex]
[tex]= (273 + 35) = 308 \ K[/tex]
Pressure [tex]P_1 = 697 mmHg[/tex]
At standard temperature and pressure;
Temperature [tex]T_2 = 273 K[/tex]
Pressure[tex]P_2[/tex] = 760 mmHg
Using the formula for a combined gas law:
[tex]\dfrac{P_1V_1}{T_1} = \dfrac{P_2V_2}{T_2}[/tex]
[tex]V_2 = \dfrac{P_1V_1T_2}{T_1P_2}[/tex]
[tex]V_2 = \dfrac{697 \ mmHg \times 140 \ mL \times 273 \ K }{308 \ K \times 760 \ mmHg}[/tex]
[tex]\mathbf{V_2 = 113.80 \ mL}[/tex]
What I know about the Alveoli and Gas exchange
Explanation:
What happens during gas exchange in the alveoli?
These are called alveoli. They inflate when a person inhales and deflate when a person exhales. During gas exchange oxygen moves from the lungs to the bloodstream. At the same time carbon dioxide passes from the blood to the lungs.
What is the role of alveoli in gas exchange?
The alveoli are where the lungs and the blood exchange oxygen and carbon dioxide during the process of breathing in and breathing out. Oxygen breathed in from the air passes through the alveoli and into the blood and travels to the tissues throughout the body.
A cylinder, with a piston pressing down with a constant pressure, is filled with 1.90 moles of a gas (n1),
and its volume is 40.0 L (V1). If 0.400 mole of gas leak out, and the pressure and temperature remain the
same, what is the final volume of the gas inside the cylinder?
Answer:
31.58 L
Explanation:
From the question given above, the following data were obtained:
Initial mole (n₁) of gas = 1.90 moles
Initial volume (V₁) = 40 L
Final mole (n₂) = 1.90 – 0.40 = 1.5 moles
Final volume (V₂) =.?
The final volume of the gas can be obtained as follow;
V₁ / n₁ = V₂ / n₂
40 / 1.9 = V₂ / 1.5
Cross multiply
1.9 × V₂ = 40 × 1.5
1.9 × V₂ = 60
Divide both side by 1.9
V₂ = 60 / 1.9
V₂ = 31.58 L
Thus, the final volume of the gas is 31.58 L
What is the full name of the molecule ATP?
Answer:
I hope this helps
Explanation:
Adenosine TriPhospahte
which type of blood vessel has a pulse
Answer:
The arteries should be your answer!
Explanation:
Give a reason for each of the following laboratory practices:
I. KMnO4 solution is not acidified with HNO3 before titration
II.FeSO4 solution is usually prepared fresh when needed
III. Alkali are not stored in glass stoped reagent bottles
Answer:
See explanation
Explanation:
The acid commonly used to acidify KMnO4 is H2SO4. The reason why HNO3 is not used is because HNO3 is itself a strong oxidizing agent. HCl is not used because it can react with KMnO4.
FeSO4 solution is usually prepared fresh when needed because if the solution is prepared and left to stand for sometime, FeSO4 is oxidized to Fe2(SO4)3 by air. Fe III does not give the brown ring test.
Alkali are not stored in glass stopped reagent bottles because very strong alkali can cause the stopper to corrode and fuse to the neck of the bottle making it very difficult to open the reagent bottle.
The element Osmium has _ neutrons in its nucleus
Answer:
114
Explanation:
no
What are the correct coefficients for the following chemical reaction:
Al +
Br2 --> __AlBr3
O 3, 3,2
O 2,3,2
0 2,2,3
O 3,2,2
Answer:
2Al + 3Br2 = 2AlBr3 so the second option is right
ANSWERED
Graph the number of A particles versus the time and the number of B particles versus the time. Plot both data sets on the same graph.
True or False: A liquid's volume does not change no matter what the shape of its container.
Answer:
true
Explanation: becuase if you add the same liquid to a small container and then add it to a big container its going to have the same liquid amount it started with
What is the value of Q when 100.0 mL of a 7.6 10-4 M Mg(NO3)2 is added to 100.0 mL of 7.1 10-4 M NaOH? (Ksp for Mg(OH)2 = 8.9 ✕ 10-12)
Answer:
Q = 4.8x10⁻¹¹
Explanation:
The solubility of Mg(OH)₂ is:
Mg(OH)₂(s) → Mg²⁺(aq) + 2OH⁻(aq)
And Ksp is:
Ksp = [Mg²⁺] [OH⁻]²
Where [] are concentrations in equilibrium
Thus, Q could be defined as:
Q = = [Mg²⁺] [OH⁻]²
Where [] are actual concentrations
[Mg(NO₃)₂] = [Mg²⁺]
And [NaOH] = [OH⁻]
Both solutions are diluted twice (Because 100mL of each solution are diluted to 200mL). The equilibrium concentrations are:
[Mg²⁺] = 7.6x10⁻⁴M / 2 = 3.8x10⁻⁴M
[OH⁻] = 7.1x10⁻⁴ / 2 = 3.55x10⁻⁴M
That means Q is:
Q = [3.8x10⁻⁴M] [3.55x10⁻⁴M]²
Q = 4.8x10⁻¹¹