Answer:
A new compound is formed
How many oxygen atoms and are present in this water molecule 2H2O?
(note* the number 2 after H is a subscript)
Answer: 4 hydrogen atoms and 2 oxygen atoms.
Explanation:
For example, two water molecules (2H2O) contain 2 • 2 = 4 hydrogen atoms and 2 • 1 = 2 oxygen atoms.
Which of the following is the best indication that a chemical change has taken place?
a. The matter changes color.
b. A mixture separates into layers.
c. The change is reversible.
d. The shape of the substance changes.
Answer:
C
Explanation:
It is C because the change is inversible, that means that it is a chemical change.
Which formula represents an alkane?
1.
C2H2
2.
C2H4
3.
C3H4
4.
С3Н8
Answer: Option 4) is correct.
Explanation: It is correct because alkanes have a general formula CnH2n+2. So, all we need to do is substitute and find out how many hydrogens are needed to make the formula an alkane. I am not really good at explaining. I am sorry If I confused you.
Alkanes are the organic compound which has general formula [tex]C_{n}H_{2n +2}[/tex] which satisfies the formula [tex]C_{3}H_{8}[/tex]. Hence [tex]C_{3}H_{8}[/tex] represents an alkane.
AlkaneAlkanes are simplest saturated hydrocarbon. Alkanes are also known as paraffins wax. Alkanes which contains only carbon and hydrogen atoms.
General Formula of AlkaneThe general formula of alkane is [tex]C_{n} H_{2n + 2}[/tex] where n = 1, 2, 3, 4.......
Consider Option 1, [tex]C_{2}H_{2}[/tex] here n = 2 now put the value of n in above formula, we get: [tex]C_{2} H_{2 \times 2 + 2}[/tex] = [tex]C_{2} H_{4 + 2}[/tex] = [tex]C_{2} H_{6}[/tex] , so option 1 does not satisfies the above formula. Hence it is incorrect. Consider Option 2, [tex]C_{2} H_{4}[/tex] here n = 2 now put the value of n in above formula, we get: [tex]C_{2} H_{2 \times 2 + 2} = C_{2} H_{4 + 2} = C_{2} H_{6}[/tex], so option 2 does not satisfies the above formula. Hence it is incorrect. Consider Option 3, [tex]C_{3} H_{4}[/tex] here n = 3 now put the value of n in above formula, we get: [tex]C_{3} H_{2 \times 3 + 2} = C_{3} H_{6 + 2} = C_{3} H_{8}[/tex], so option 3 does not satisfies the above formula. Hence it is incorrect. Consider Option 4, [tex]C_{3} H_{8}[/tex] here n = 3 now put the value of n in above formula, we get: [tex]C_{3} H_{2 \times 3 + 2} = C_{3} H_{6 + 2} = C_{3} H_{8}[/tex], so option 4 satisfies the above formula. Hence it is correct.Thus, from the above conclusion we can see that option 4 [tex]C_{3}H_{8}[/tex] represents an alkane.
Learn more about the alkane here: https://brainly.com/question/16837399
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After constructing the circuit, Aliyah and Jeremy noticed that the light bulb stays on all the time. This means the batteries will get used up when the flashlight does not need to be on. What is something Aliyah and Jeremy can do to solve this problem?
Answer: Implement a switch
Explanation:
This forms a circuit break or way to easily turn the flow of electricity on or off.
Which of the following is most likely a homogeneous mixture?
O A. A tossed vegetable salad
B. Chunky peanut butter
O C. Chocolate chip cookies
OD. A vanilla milkshake
Answer:
D)A vanilla milkshake
Explanation:
An exothermic reaction releases 13,450J of heat. How many calories of energy are released? A) 5 56,274 calories B)1,244 caloriesC) 134,500 caloriesD) 3,215 calories
Answer:
The correct option is;
D) 3,215 calories
Explanation:
Here we are required to convert 13,450 J to calories
1 calorie is the amount of heat required to raise the temperature of 1 gram of water by 1°C
Therefore, 1 calorie = 4.184 Joules
Hence, 1 Joule = 1/4.184 calorie for which we have;
13,450 J = 13,450 × 1/4.184 calories = 13,450/4.184 calorie
13,450 J = 3,214.63 calories
Rounding up to the nearest whole number, we have;
13,450 J ≈ 3,215 calories.
What reactants would you use to produce Mg(No3)2 and H2
Explanation:
This is a single replacement reaction, so we just have to switch Mg and H₂. When we do so, we get HNO₃ and Mg as our reactants. Hope this helps!
How many grams of NaCl are needed to prepare 1.20 liters of a 2.00 M solution?
Answer:
140 grams NaCl is needed
Explanation:
i used this How many grams of NaCl in 50 mL of 0.75 M NaCl solution? The MOLARITY of a solution is determined by the ratio of moles of solute, (the material being dissolved), compared to the liters of solution. the equation is M = mol L For this NaCl solution we have a Molarity of 0.75 in 50 mL of solution. Then i multiplied it by the correct amount
Which of the following statements is true?
Sound vibrations are changed into electrical impulses by the eardrum.
It is dangerous to listen to sounds over 160 dBs.
High-pitched sounds have low frequencies.
All of the above.
Answer:
all of the above!! :)))
Explanation:
Question 3 of 10
5 Points
Match the approximate percentage of the world's water to where it is stored.
Salt water
97 percent
Ice caps and
glaciers
2 percent
Fresh liquid
water
1 percent
Answer:
salt water 97%
fresh water 1%
frozen 2%
Explanation:
explain a natural process, while
describe a natural process.
Answer:
a natural process is water cycle.
Explanation:
during this process,water evaporates from different water bodies ,when the warm water rises,the cold and heavier water comes down to take its place.On the other hand,the warm water on rising,changes to water vapour.
This water vapour helps in the formation of clouds .
When the cloud becomes heavy and is not able to hold the water vapour, it falls down as rain or snow depending upon the climate and atmospheric temperature.
This process continues over and over again
What does a dissolved salt look like?
A. The salt crystals are surrounded by water molecules.
B. The salt crystals separate into salt molecules in the water.
C. The salt separates into ions that settle to the bottom
D. The ions in the salt are surrounded by water molecules.
Answer:
I want to say your answer is B)
The answer is D because the ions in the salt will be surrounded by water molecules
Dissolution in water occurs as a result of ionic interactions. This means that the ions (charged atoms) of the solute has to interact with the ions of water for the solute to dissolve. Based on this principle, only polar compounds can dissolve in water.
According to this question, salt is polar because it contains positive (+) and negative (-) ions. Hence, when placed in water, these ions will interact with the ions of water i.e. H+ and OH-. This causes dissolution of salt in water to form salt solution.
Hence, a dissolved salt will look like "ions in the salt are surrounded by water molecules".
Learn more: https://brainly.com/question/8620871
You can scratch graphite with your fingernail. What does this tell you about graphite? A. It breaks easily. B. It’s not very hard. C. It’s not very lustrous. D. It doesn’t have much texture.
Answer:
A and B
Explanation:
Graphite (like in a pencil) is a material that can easily be smudged and shaded just by smudging it a little. Therefore I believe it's A or B
Answer:
Its C
Explanation:
Which of the following compounds contains covalent bonds? *
Cs₂O
Fe₂O₃
NaCl
CCl₄
NaCI
Explanation:
I just worked this out the day before
Identity the anode and cathode
Answer:
Pb(s) ---> Pb+2 + 2e- is the anode
Cu+2(aq) + 2e- ---> Cu(s) is the cathode
Two friends are arguing about the structure of the universe. Caleb says that the universe is made of many galaxies that are
made of millions of stars and many galaxies that are made of millions of planets. Maria says that he is wrong because
galaxies like the Milky Way are made up of millions of universes with millions of stars.
Which best describes the error(s) that were made in this conversation?
Caleb is incorrect when he says that some galaxies are made of stars and some are made of planets, and Maria is
incorrect when she says that the Milky Way is a galaxy.
Maria is incorrect when she says that galaxies are made up of universes
Caleb is incorrect when he says that some galaxies are made of stars and some are made of planets and Maria is
incorrect when she says that galaxies are made up of universes
Maria is incorrect when she says that the Milky Way is a galaxy
Answer:
i put b but im not that sure
Explanation:
How many moles of potassium nitrate are required to make 550 mL of a 2.1M solution?
Answer:
1.155 moles of potassium nitrate are required to make 550 mL of a 2.1M solution.
Explanation:
In a mixture, the chemical present in the greatest amount is called a solvent, while the other components are called solutes.
Molarity is a unit of concentration of a solution and indicates the amount of moles of solute that appear dissolved in each liter of the mixture. In other words, the Molarity (M) or Molar Concentration is the number of moles of solute that are dissolved in a given volume.
The Molarity of a solution is determined by the following expression:
[tex]Molatity( M)=\frac{number of moles of solute}{Volume}[/tex]
Molarity is expressed in units ([tex]\frac{moles}{liter}[/tex]).
In this case:
Molarity= 2.1 Mnumber of moles of solute= ?Volume= 550 mL= 0.550 L (being 1L=1000 mL)Replacing:
[tex]2.1 M= 2.1 \frac{moles}{liter} =\frac{number of moles of solute}{0.550 liters}[/tex]
Solving:
number of moles of solute= 2.1 M* 0.550 L
number of moles of solute= 1.155 moles
1.155 moles of potassium nitrate are required to make 550 mL of a 2.1M solution.
60.0 g of NH Cl are dissolved in 100 grams of water at 60.0° C. This solution is
A
supersaturated
B
saturated
С
unsaturated
D
none of the above
Answer:
B) is the correct answer
What causes eclipses? select three options
Answer:
The first, second, and 4th option
Explanation:
An insulator,
Keeps electrons inside the nucleus of an atom
Allow electrons to move easily through an object
Is when electrons cannot move through objects easily
What specifically do vaccines contain which cause your body to become
immune to specific pathogens? *
Answer:
I'm not entirely sure, but I've heard that vaccines contain very weak amounts of the virus in order to expose your body to it, so that your body can become immune to it before being exposed to the real thing.
So basically, a flu shot contains a weak version of influenza.
I don't know this for sure, but hopefully this helps!
What is the molariity of a 50.0 mL aqueous solution containing 10.0 grams of hydrogen peroxide, H2O2?
Answer:
6 mol/L
Explanation:
You should know or have the equation to solve for Molarity which is;
M = n/v (M: Molarity) (n: moles of solute) (v: Liters of solute)
You can start off differently but I would start by converting the mL to L. This is your "v" value.
50.0 mL/ 1000 mL = 0.05 L
Now, you have to convert grams to moles in order to solve for molarity (M).
1.) On the periodic table find the molecular weights of H and O.
H= 1.01 g/mol O= 16.00 g/mol
2.) Multiply them and then add them together to have their combined molecular weights. (You have to multiply by 2 because of their equation; H2O2).
2(1.01) + 2(16.00)= 34.02 g/mol
3.) Now, you're going to use the "picket fence method" or whichever your teacher taught you to convert from grams to moles. This will be your "n" value. (I cannot show it on here without it looking weird, so my sincere apologies.)
10.0 g/ 34.02 g = 0.2939 mol
4.)You are now going to plug in your answers into the equation for Molarity.
M= 0.2939 mol / 0.05 L = 5.878 mol/L
5.) I am sure your professor might be a stickler so for sig figs sake when you multiply or divide use the smallest amount of sig figs you see which is 1. Round 5.878 to 6 mol/L
Sorry this explanation is very long let me know if you need a better more written out explanation.
Describe the interactions with the Sun, Earth and Moon system that result in Lunar Cycle / Phases.
Answer: The tides are another interaction in the sun-earth-moon system. The tides happen because the moon and sun pull on the oceans, causing them to rise and fall each day. The moon has a bigger effect than the sun because it is closer. The angle of the sun as the earth orbits over the course of a year causes the seasons.
Explanation:
Relate dark matter to the development of the universe after the Big Bang. In 3-5 sentences, speculate on how the development of the universe would have been different if there had been no dark matter. In your answer, use the term structures.
Please answer if you do i will mark you as brainliest
Answer:
Without dark matter galaxies would loose an extreme amount of gas required to create stars.
Without dark matter the universe wont have as many galaxies clumped together forming larger versions of those galaxies. This would cause a change in the structure of the "skeleton" of the web.
(Hope this can help, I didn't do exactly as it is said to because that is your job)
:)
Explanation:
Forbes gives somewhat of an explanation if you are curious.
(Ethan Siegal, "The Universe Would Be Very Different Without Dark Matter", Forbes)
Dark matter makes up most of matter in the universe and is found by a quarter of the total composition of the space. After the event of the big bang, the universe expanded and dark matter grew.
Dark matter accounts for about 85% of the matter in the universe. Its presence can be felt in the gravitational effects. Dark matter doesn't interact with the electromagnetic field. After the big bang event, the dark matter still can be found in larger galaxies and contest about 26% of mass-energy and 69% of dark energy. If there had been no dark matter there would be no structure of the cosmic web of galaxies. That is there would be no connection between the galaxies and would remain in isolated fragments.Thus dark matter is a link within and with the comic web.
Learn more about the dark matter and its development-related after the big bang event
brainly.com/question/16725768.
I need simple answers that a 14-year-old would understand.
What are valence electrons?
What is the difference between the Rutherford and Thompson plum pudding model?
What relative scale for atoms do chemists use? Why do they use this?
Compare and contrast alpha, beta and gamma decay of radionuclides.
Explain why radiation is dangerous for living cells but can be applied to treat people with some forms of cancer.
Explain why oxygen atoms ionise to form the oxide ion with a charge of –2. Identify if oxide is an anion or a cation.
Answer:
1. The Nummber of electrons present in the outermost shell is called Valence electrons.
2. Thomson model:
Thomson model of atom is the model which states that electrons are embedded in a positively charged solid material which is spherical in shape.
Rutherford model
Rutherford model of atom is the model which explains that there is a nucleus in the center of the atom and electrons are located around the nucleus.
3. Relative atomic mass. Atoms have very little mass , so they're difficult to measure accurately. Instead, chemists use a scale. On this scale the mass of a 12C atom is exactly 12.
4. Difference between Alpha, Beta and Gamma radioactive decay:
Alpha decay forms new element with two fewer protons and two fewer neutrons;
Beta decay forms new element with one more proton and one fewer neutron.
Gamma decay forms NO new element, but now the element has less energy because energy is released as gamma rays.
Gamma radiation has the highest penetration power, Beta decay goes the second, alpha decay the last. However, alpha particles make the most damage even if it has the lowest penetration power among the three.
5. This species has a 2− charge on it, so it is an anion. Anions are named using the stem of the element name with the suffix -ide added. This is the oxide anion.
Hope it helps....Pls Mark as Brainliest!! I Have answered all your question in the Simplest way i could...
In the reaction N2 + 3H2 - 2NH3, how many
grams of H, are needed to produce exactly I mole
of ammonia?
A. lg
B. 2g
C.3g
D.4g
Answer:
B. 2g
Explanation:
So first you have to find the mole to mole ratio then convert it to grams if that makes sense. So the mole to mole ratio is 2 ammonia to 3 hydrogen gas. So then after you do that conversion you can solve for grams then. Sorry I am not that great at explaining.
EMERGENCY: I WILL FAIL: PLS HELP WILL MARK BRAINLIEST JUST PLS HELP
Answer:
condensation: moisture builds up on window; dew forms on blades of grass
deposition: snow is made inside a cloud; frst froms on window?
Explanation:
I need the correct answer
Answer:
d.
Explanation:
They can be spread through contaminated surfaces.
Answer:
d
Explanation: pathogens csnnot be spread be sontaminated surfesec
Which is produced by nuclear fusion?
A. hydrogen
B. electricity
C.
solar radiation
D. gasoline
Answer:
c
Explanation:
what is the compound of p2o5
Answer:
Phosphorus pentoxide is a chemical compound with molecular formula P4O5 (with its common name derived from its empirical formula, P4O5). This white crystalline solid is the anhydride of phosphoric acid. It is a powerful dessicant and dehydrating agent.
Explanation:
it would be phosphoric acid.
