Answer:
B. chemical
Explanation:
Chemical change cannot go back to its original form
Answer:
B
Explanation:
bubbles is a form of chemical change :)
The burning of a sample of propane generated 1 04.6 kJ of heat. All of this heat was used to heat 500.0 g of water that had an initial temperature of 20.0/C. What was the final temperature of the water?
Answer: 70.0°C
Explanation:
Quantity of heat = Mass * Specific heat * Change in temperature
Quantity of heat = 104.6 KJ
Mass = 500.0 g
Specific heat of water is 4.18 J/g°C
Change in temperature assuming final temperature is x = x - 20
Units should be in grams and joules:
104,600 = 500 * 4.18 * (x - 20)
104,600 = 2,090 * (x - 20)
x - 20 = 104,600/2,090
x = 104,600/2,090 + 20
x = 69.8
= 70.0°C
Which ion is a cation? A. Ca2+ B. Cl2 C. S2- D. Br-
Answer:
Ca2+ is cation
Explanation:
Because cation contain positive charge.
Can you help me balance the following chemical equation?!
Al(OH)3 + H2CO3 = Al2(CO3)3 + H2O
Answer: [tex]2Al(OH)_3+3H_2CO_3\rightarrow Al_2(CO_3)_3+6H_2O[/tex]
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants.
The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
The balanced chemical equation will be :
[tex]2Al(OH)_3+3H_2CO_3\rightarrow Al_2(CO_3)_3+6H_2O[/tex]
How many moles of chlorine atoms are in 6.3 × 1023 chlorine molecules?
Answer:
(6.3x10^23)/(6.02x10^23) = 1.047 mol Cl
The number of moles of the chlorine atoms in the 6.022 × 10²³ molecules of chlorine is equal to 2.10 mol.
What is Avogadro's number?Avogadro’s number can be used to express the number of entities in one mole of any substance and these units can be atoms, molecules, ions, electrons, or protons, depending upon the kind of chemical reaction or reactant and product.
The Avogadro’s constant has a numerical value approximately equal to 6.022× 10²³ mol⁻¹.
Given, the number of molecules of chlorine = 6.3× 10²³
As the one chlorine mole has chlorine atoms = 2
The number of moles of chlorine molecules in 6.3× 10²³ will be :
= 6.3× 10²³/ 6.022× 10²³ = 1.05 moles
One mole of chlorine molecules has Cl atoms = 2 moles
1.05 moles of chlorine molecules have Cl atoms = 2 × 1.05 = 2.10 mol
Therefore, the number of moles of Chlorine atoms is equal to 2.10.
Learn more about Avogadro's number, here:
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Please help! Due today. Look at the image:
Reuploaded
Answer:
3
Explanation:
2+2=4-1=3 quick maths
PLZ HELP!
How do you think changing the angle of a ramp will affect work done?
Answer: The steepness of a ramp affects it by making it easier or harder.
Explanation: It's a bit situational. If you were going up a steep ramp with a heavy load, it will increase the work necessary, whereas if you were going down a ramp, it would decrease the work necessary. If you need this simply put, think about biking up and down a hill. It would be easier going down than up.
write one use of quick lime
Answer:
calcium supplements
Explanation:
If you look at the periodic table today which elements would best represent a triad as predicted by Dobereiner?
A. Hydrogen Oxygen Nitrogen
B. Nickel Copper Zinc
C. Aluminum Gallium Indium
D. Neptunium Plutonium Americium
E. All of them are triads
HELP ME PLEASE!!!!
Answer: B. Nickel Copper Zinc
Explanation:
Dobereiner's triads was a group of three elements. Dobereiner said that the relative atomic mass of the middle element in each triad was average of the relative atomic masses of the other two elements.
Thus if A, B and C forms Dobereiner's triads, the mass of B is average of mass of A and C.
A. Hydrogen Oxygen Nitrogen:
mass of oxygen = 15.999
mass of oxygen according to Dobereiner = [tex]\frac{1.008+14.007}{2}=7.5075[/tex]
B. Nickel Copper Zinc
mass of copper = 63.5
mass of copper according to Dobereiner = [tex]\frac{58.7+65.38}{2}=62.04[/tex]
C. Aluminum Gallium Indium
mass of gallium = 69.72
mass of gallium according to Dobereiner = [tex]\frac{26.98+114.82}{2}=84.39[/tex]
D. Neptunium Plutonium Americium
mass of Plutonium = 244
mass of Plutonium according to Dobereiner = [tex]\frac{243+237.04}{2}=240.02[/tex]
HELP HELP DUE IN 5 MINS I WILL MARK BRAINLIEST
Just say that it went below 0/average.
When Earth receives energy from the Sun,
Answer:
100% of the energy entering earth's atmosphere comes from the sun. ~50% of the incoming energy is absorbed by the earth's surface i.e. the land and oceans. ~30% is directly reflected back to space by clouds, the earth's surface and different gases and particles in the atmosphere (the earth's albedo is 0.3 on average)
Explanation:
:)
A bicycle tire has a pressure of 18.5 lb/in^2 What's the pressure in torr?
Answer:
B y is a complete collection for your time and energy for the spread of Islam in the Horn of the following to make sure
RODINNIS
COURSES
onal Science
Attempt 1 of 2
Which of the following distinctions are used to identify sedimentary rock? Select all that apply.
o where is was formed
conditions it was formed under
n when it was formed
what it is composed of
how many layers it consists of
NEED HELP ASAP (check the picture)
where it was formed and. conditions it was formed under
PLZ HELP THIS IS DUE IN 6 MINS
The majority of elements on the periodic table are ______________ (metals, nonmetals, or metalloids).
Answer:
nobel gases ,non metals and metaliods
2.1 x 10^-3 x 2 x 10^2 =
a)
4.2 x 10^-5
b)
4.2 x 10^-1
c)
4.2 x 10^1
d)
4.2 x 10^-6
Answer:
I believe it is B
Explanation:
hope it helps. please let me know if it's wrong
What is the difference between condensation and evaporation?
Condensation is the phase change from gas to a liquid, whereas evaporation is the phase change from liquid to gas.
HELP!!! 2Mg+O2->2MgO
What are the products of this reaction??
WILL GIVE BRAINLEST
Answer:
the products which is formed in the given reaction is MgO ( magnesium oxide )
Explanation:
when magnesium metal reacts with oxygen present in air it burns with a white dazzling flame
to form white powder of magnesium oxide (MgO)
here's the balanced chemical reaction for it
2Mg+O2->2MgO
The general area of the atom (outside the nucleus) where the e- are located is the — and —
under which conditions would the solubility of a gas be greatest
Answer:
when there is high pressure and low temperature then the solubility of a gas will be greatest.
Answer:
B
Explanation:
edg 2021
what is chemistry?
in your own word please 2-3 sentence
Answer:
the science that deals with the properties, composition, and structure of substances they undergo, and the energy that is released or absorbed during these processes.
Explanation:
Answer:
Is the scientific branch that deals with the composition and decomposition of elements and compounds in nature
Explain five physical and/or chemical properties that you need to consider for the substances before using them as construction materials for buildings
Answer: There are many properties of a metal which is taken into consideration when it is used for construction
Explanation:
The properties can be physical, chemical, et cetera. The physical properties that is considered are:
1. Durability: It can be defined as the property of the material to withstand the atmospheric pressure and other factors.
2. Density: The ratio of mass by volume of a material (homogeneous material) is called as density.
3. Fire resistance: The ability of the material to withstand in fire without changing its size or shape.
4. Weather resistance: The ability of the material to withstand the weather which could be variable round the year.
5.Water absorption: The ability of the material to absorb water and retain it.
Significant Figures
1. Indicate how many significant figures there are in cach of the following measured values.
un
246.32
5
1.008
700000
107.854
3
0.00340
3
350.670
4
100.3
14.600
1.0000
6
0.678
0.0001
320001
Which of the following is a physical change?
a. burning gasoline
b. cooking an egg
c. decomposing meat
d. evaporating water
Apart from cost, give three reasons why steel should be recycled
Answer:
Well, acutally it shouldnt..but why it should be recycled is because 1. you can use it for many nessactities such as cars and blades, and bikes
You should also recycle it for, scrap parts! so just in case if you need recycled steel ya know where to get it
Lastly, you should recycle steel because of its value. If you recycle steel then melt it, and make well i dont know, a blade out it, you might have just made something, and then think, "Well that was fun and easy, i wanna use more recycled items to build or forge things
Explanation:
Hope this helps and pls mark brainlest!
Answer:
i think because its cause pollution
Explanation:
when making steel a lot of pollution goes in the atmosphere so if you recyle the the steel we may less pollution [ im only 12 so im sorry if this was wrong]
18. Which statement about photosynthesis is FALSE?
a
Tilmy green pigment chlorophyll captures light
energy
b Oxygen is needed as a reactant to produce
glucose
The process converts light energy from the
csun into chemical energy in the bonds of
glucose.
d
Carbon dioxide is needed as a reactant to
produce glucose.
Which statement about photosynthesis is FALSE?
Answer:
b. Oxygen is needed as a reactant to produce
glucose is the incorrect statement here
Explanation:
plants uses simple raw materials to prepare their food , which includes water ( H2O ) and Carbon dioxide ( CO2 ).
and traps sunlight by Green pigments known as chlorophyll and stores these energy in bonds of glucose molecules
so ,
after this reaction glucose and oxygen is formed as products
● hence we conclude that Oxygen is not needed as a reactant to produce glucose , oxygen is the bi product formed during photosynthesis.
what element has three valence electrons in the second energy level.
Answer:
Boron
Explanation:
Hope that helps
Answer:
Boron.
Explanation:
2 energy shells
1st energy she'll 2 electrons
2nd energy shell 3 electrons
Carlita’s body is made up of many cells. What is one thing all her cells have in common?
Answer:
All of them have a nucleus..
Explanation:
Pretty simple stuff. There's no cell without one.
Carlita’s body is made up of many cells. The one thing that all her cells have in common is they have the same kind of genes.
What are genes?Genes are tiny pieces of spherical hereditary material that are bead-shaped and found on chromosomes. They hold the organism's genetic makeup. The number of genes on each chromosome is incalculable.
The hereditary material that makes up chromosomes is arranged in x shapes inside the nucleus. DNA, genes, and proteins make it up. An organism's genotype is distinct from other organisms because of its distinct genetic makeup, and this distinction can be passed down from one generation to the next.
Traits may be influenced by genes, the environment, or a mixture of the two. Quantitative features can also be qualitative, such as eye colour (such as height or blood pressure).
Therefore, numerous cells make up Carlita's body. Her cells all share the same type of genes, which is the only thing that unites them.
To learn more about genes, refer to the link:
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teachers instructions - “ clear my examples and replace with your own words “ you get brainliest if I get good grade :)
Answer:
can you give me more clearence on what is going on
Explanation:
During ____, the chromatin condenses to make ____.
prophase, chromosomes
metaphase, chromosomes
prophase, DNA
metaphase, DNA
As the blood travels through your body, it _______.
A. picks up nutrients, water, and waste materials
B. pulmonary circulation
C. the lungs, where it picks up oxygen again
D. capillaries
E. 5
F. systemic circulation
Answer:
C. the lungs where it picks up oxygen again
Which circuit hook-up design will have the brightest light bulb?A - 1 battery 1 bulb, B - 2 batteries 1 bulb, C - 3 batteries one bulb, D 2 batteries the bulb is on the other end, E 1 battery and 1 bulb on the other end
Question 5 options:
A
B
C
D
E
Heres another for you guys!
Answer:
I believe it is E because the battery has a wire, a power source(the battery), and a bulb connected together thus making a full series circuit. Furthermore, the more batteries they are to a series circuit, the more dimmer the light bulbs will be.