what is an example of a combustion reaction
if possible, can it come with an explanation pls
Answer:
An example of a combustion reaction is the burning wood in a fire.
Explanation:
In the combustion reaction, the carbohydrates in wood combine with oxygen to create water and carbon dioxide. This reaction is very energetic, and it generates heat and light as it releases said energy.
Hope this helps! Have a nice day! (And please mark me brainliest)
When scientist want to measure the brightness of a star while considering the distance from the observer what are they going to
measure?
O Absolute brightness
O Apparent brightness
O Absolute magnitude
O Apparent magnitude
Answer:
apparent brightness
Explanation:
thats it not sure buttt
Answer:
This wide-field view of the sky around the bright star Alpha Centauri was created from photographic images forming part of the Digitized Sky Survey 2. The star appears so big just because of the scattering of light by the telescope's optics as well as in the photographic emulsion. Alpha Centauri is the closest star system to the Solar System. Image released Oct. 17, 2012. (Image credit: ESO/Digitized Sky Survey 2)
A glance at the night sky above Earth shows that some stars are much brighter than others. However, the brightness of a star depends on its composition and how far it is from the planet.
Astronomers define star brightness in terms of apparent magnitude — how bright the star appears from Earth — and absolute magnitude — how bright the star appears at a standard distance of 32.6 light-years, or 10 parsecs. (A light-year is the distance light travels in one year — about 6 trillion miles, or 10 trillion kilometers.) Astronomers also measure luminosity — the amount of energy (light) that a star emits from its surface.
Measuring star brightness is an ancient idea, but today astronomers use more precise tools to obtain the calculation.

From Greek to modern times
More than 2,000 years ago, the Greek astronomer Hipparchus was the first to make a catalog of stars according to their brightness, according to Dave Rothstein, who participated in Cornell University's "Ask An Astronomer" website in 2003.
"Basically, he looked at the stars in the sky and classified them by how bright they appear — the brightest stars were 'magnitude 1,' the next brightest were 'magnitude 2,' etc., down to 'magnitude 6,' which were the faintest stars he could see," Rothstein wrote.
Human eyes, however, are not very discerning. Large differences in brightness actually appear much smaller using this scale, Rothstein said. Light-sensitive charged-coupled devices (CCDs) inside digital cameras measure the amount of light coming from stars, and can provide a more precise definition of brightness.
Using this scale, astronomers now define five magnitudes' difference as having a brightness ratio of 100. Vega was used as the reference star for the scale. Initially it had a magnitude of 0, but more precise instrumentation changed that to 0.3.
Orion is the brightest and most beautiful of the winter constellations. Some of its stars, including Betelgeuse and Rigel, are among the brightest stars. (Image credit: Starry Night Software)
Apparent magnitude vs. absolute magnitude

When taking Earth as a reference point, however, the scale of magnitude fails to account for the true differences in brightness between stars. The apparent brightness, or apparent magnitude, depends on the location of the observer. Different observers will come up with a different measurement, depending on their locations and distance from the star. Stars that are closer to Earth, but fainter, could appear brighter than far more luminous ones that are far away.
"It is the 'true' brightness — with the distance dependence factored out — that is of most interest to us as astronomers," stated an online course on astronomy from the University of Tennessee.
"Therefore, it is useful to establish a convention whereby we can compare two stars on the same footing, without variations in brightness due to differing distances complicating the issue."
Explanation:
HOPE IT HELPS
What are two things in nature that solar energy powers?
Answer: light and heat
Explanation:Our sun is the source of all life on Earth, and solar energy is useful to us in many different ways. The sun creates two main types of energy - light and heat - that we can harness for many activities ranging from photosynthesis in plants to creating electricity with photovoltaic (PV) cells to heating water and food.
Use what you know about the orbits of Earth and the moon to sort the phrases into the correct Category.
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Actually Welcome to the Concept of the Astrophysics.
Let's categorize them eventually ==>
1.) Earth ==> 1.) travels around the Sun
2.) takes 365.25 days .
2.) Moon ===> 1.) travels around the Earth
2.) Takes 27.3 days.
10pts! Will give brainllest if you are right! Please come quicklyyyy!
How are speed and velocity related?
A. they're exactly the same
B. velocity = speed and direction
C. speed = velocity and direction
D. direction = speed and velocity
Answer:
Hey there :))
Speed and Velocity are related in a lot of ways distance and displacement are. Speed is a scalar and velocity is a vector. They both represent a way to measure the change in position of an object relative to time.
Which two types of waves require matter in order to travel?
О A. Light Waves
О B. Water Waves
О C. Electromagnetic Waves
О D. Sound Waves
Answer:
water waves and sound waves
hiii please help i’ll give brainliest
Answer:
C option
Explanation:
Can somebody sort these from non-metals to metals?
Sonorous, low melting point, high density, brittle, dull, malleable, basic oxide
balance the following equations
1) 2KI + Cl2 → 2KCl I2
2) 2C2H6 + 7O2 → 4CO2 + 6H2O
3) 3Mg(NO3)2 + 2K3PO4 → Mg3(PO4)2 + 6KNO3
Can the structure of an atom be broken down into smaller parts?
Answer
yes it can because it can be split in to neutrons and electrons.
Explanation:
The thin muscular wall that separates the right side of the heart from the left side is called the
Explain how cells are organized within a multicellular organisms
Answer:
For any multicellular organism to survive, different cells must work together. The right type of cell must be in the right place to do the work that needs to be done. Organization starts with the cell. Cells in multicellular organisms are specialized for a specific function.
Explanation:
Answer:
Cells in multicellular organisms are organised into tissues and tissues are organised into organs, organs are organised into organ system, and finally, organ systems are organised into an organism
advantages of artificial fertilizers?
Answer:
they improve soil texture
Explanation:
that's it helps to hold
water longer and and increase the soil bacteria and fungal activity in the soil so they do not only assist your plants , they help the soil.
A neutral atom possesses an atomic number of 13 and an atomie mass of 27. Three electrons are lost.
From what region of the atom are they lost?
outside the atom
inside the nucleus
outside the nucleus
both inside and outside the nucleus
CH4 + O2 = H2O + CO2, turn this into a balanced equation and show work.
Answer:
CH4 + 2O2 = 2H2O + CO2
How many grams are in 2.2 moles of magnesium hydroxide?
128.33g
26.51g
0.04g
Answer:
128.33g
Explanation:
HELP FAST!
This food chain is one part of a ____ within an ecosystem.
A)
biome
B)
community
C)
population
D)
species
Answer:
Species
Explanation:
How many reactants are there in a single replacement reaction?
Answer:
One reactant
Explanation:
Which organelle is found in both prokaryotes and eukaryotes?
a. Mitochondria b. Ribosomes c. Cell
Answer: It would be ribosomes..
Explanation:
A larger bullet does not necessarily have more momentum than a smaller bullet Explain why
Answer:
yes
Explanation:
a larger bullet weighs more then a smaller bullet so the smaller bullet goes faster.
Answer:
Explanation:
Momentum is dependent on mass and velocity. So, the smaller bullet can be moving at a much greater speed than the larger one.
What was important about the Hydrogen bright line emission spectrum?
Answer:
The emission spectrum lines are the changes in the quantum energy levels of the single electron in the Hydrogen atom.
Explanation:
Electrons move around the hydrogen atom in electron waves patterns. These waves occur in distinct quantum energy levels.
The change from one quantum energy level to another energy level has a definite energy level change. There is a wave length associated with each change in energy levels. These wave lengths have a color associated with them.
Low energy level changes have long wave lengths associated with them giving red and orange colors.
High energy level changes have short wave lengths associated with them giving blue and violet colors.
Note each atom has a unique emission spectrum associated with the energy levels and electron structure of the atom. Helium was first discovered by looking at its emission spectrum as seen in the sun.
Explanation:
What is changes in a chemical reaction
The Big Bang Theory is a hypothesis that states that all matter
and energy were at one time compressed into a small volume
and then _________
Answer:
I’m not sure how they want you to answer the fill in blank.
Explanation:
The Big Bang is a theory where 14 billions years ago all matter and energy in the universe was compressed into an extremely small volume that exploded and began expanding in all directions.
The big bang theory is a hypothesis that states that all matter and energy were compressed into a small volume at one time and then expanded outward.
What is Big Bang Theory?The big bang model of the universe can be described as the model to identify the beginning of the universe. The big bang model is a cosmological model which is described by the software development life cycle.
The Big Bang theory is the dominant model of the observable universe from its beginnings to large-scale evolution. This model explains how the universe is expanded from a state of high density and temperature. It provides an explanation for phenomena, such as cosmic microwave background radiation, the abundance of light elements, and large-scale structure.
Due to the big bang as we know, the universe has been created existing about 12 - 15 billion years ago. According to the theory that the Big bang was a gigantic explosion that formed all of the energy and mass in less than a second in the universe.
Learn more about Big Bang Theory, here:
https://brainly.com/question/1160650
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Select the correct answer.
Which substance is most likely to form in a precipitation reaction?
A.
calcium nitrate
B.
copper(I) nitrate
C.
iron(I) chloride
D.
iron(II) sulfide
E.
potassium sulfate
Answer:
C.
Explanation:
Iron is most likely to form a precipitation reaction.
What role does energy play in sound? Pls help this is due today
A. Sound waves have nothing to do with energy.
B. Sound waves carry energy.
C. Energy is present in loud sounds only.
D. Energy is present in high-pitched sounds but not in low-pitched sounds.
Answer:
pretty sure it is letter B
Answer:
B
Explanation:
A sample of gas contains 6.25 × 10-3 mol in a 500.0 mL flask at 265°C.
Solve the problem for the pressure of oxygen.
in kPa plz
Answer:
The pressure of gas in kilopascals is 55.9
Explanation:
variables given :
volume
temperature
moles
unknown variables :
pressure
Select the correct algebraic form for the equation to be used for this calculation.
p= nRT/V
Solve the problem for the pressure of oxygen.
Answer:
55.9 kPagive full experimental details of how you would prepare a aluminum chloride from aluminum
Answer:
hello hello hello hello hello hello hello
How much energy is needed to heat 9.3 grams of silver metal from 21 °C to 52 °C, if the
specific heat of silver metal is 0.240 J/g °C?
Question 5
4 pts
How much heat must be added if 160 grams of water is heated from 24 °C to 85 °C?
(The specific heat of water is 4.184 J/g °C)
Look at picture
ASAP please will mark as brainlist don’t got much time
Answer:
question 4. 69.19J
question 5. 40835.84J
Explanation:
question4.
heat needed = mass × specific heat capacity × change in temperature
= 9.3× 0.240×(52-21)
=69.192J
question 5.
heat added = 160× 4.184×(85-24)
= 40835.84J
What is the result of the following calculation? Record to the correct number of significant figures.
7.830 g x 1.041 = ?
Answer:
8.15103
g
x
Explanation:
How many molecules are in 48.0 grams of NaOH?