Answer:
Chemical reactions almost always have a change in energy between products and reactants. The total energy of a system must remain the same and sometimes a chemical reaction will absorb or release energy as light, heat or both. The energy change in a chemical reaction is caused by the amount of stored energy between the products and the reactants.
Explanation:
3. In an exercise to teach students how to use and analytical balance, the instructor
gives a student a quarter which has been pre-weighed as 5.6026 g. The weight that the
student obtains for the same quarter is 5.6013 g. What is the percent error in the
students reading?
Answer:
The percent error is 0.023%.
Explanation:
Pre-weighed of a quarter is 5.6026 g.
The weight that the student obtains for the same quarter is 5.6013 g.
We need to find the percent error in the students reading. It is given by the formula as follows :
[tex]\%=\dfrac{|\text{original value-calculated value}|}{\text{original value}}\times 100[/tex]
Putting all the values, we get :
[tex]\%=\dfrac{5.6026 -5.6013 }{5.6026 }\times 100\\\\\%=0.023\%[/tex]
So, the percent error is 0.023%.
How to find the number of atoms?
To find the number of atoms, we multiple the number of mols by Avogadro's number, about 6.02x10^23
Mark Brainliest!
Answer:
to calculate the numbers of atoms in a sample, divide it's weight in grams by the amu atomic mass from the periodic table, then multiply the result by avogadro's number: 6.0 × 10^24
A physical change is easier / more difficult to reverse than a chemical change.
Answer:
the answer is that a physical change is easier to reverse then a chemical change.
Explanation: In order for a physical change to take place it's easier to just undo what happened then if it was a chemical change because in order for very few chemical changes to reverse to it's original substance you would need another chemical change.
What kinds of reactions are studied in electrochemistry?
A. Oxidation-reduction reactions
B. Precipitation reactions
C. Decomposition reactions
D. Double-replacement reactions
(Answer is A)
Answer:A
Explanation: A P E X
The first column of the periodic table is called the
Count the total number of atoms in CH4:
Answer:
5 atoms
Explanation:
there is 1 carbon atom and 4 hydrogen atoms
25 POINTS
Boyd takes additional measurements of the mass of product formed in a reaction. He uses a balance that has smaller graduations than the first balance he used.
What is Boyd most likely trying to change?
Options:
He is trying to increase his accuracy but not his precision.
He is trying to increase his precision but not his accuracy.
He is trying to decrease his precision and increase his accuracy.
He is trying to increase his precision and decrease his accuracy.
Answer:
The correct option is A: "He is trying to increase his accuracy but not his precision"
Explanation:
Accuracy of measurement is when the value of the measurement is close to the actual value of that measurement while precision is when the experiment is repeated using the same instrument but obtaining different values.
When Boyd changed the weighing balance in his experiment to a smaller one, the smaller weighing balance has better accuracy (smaller graduations) than the initially used one because the smaller weighing balance will provide a value close to the actual value of the mass of the product. If he had, however, repeated the experiment without changing the weighing balance, he would have sought to increase his precision.
From the description above, it can be said that Boyd was trying to increase his accuracy but not his precision
Answer:
The correct option is A: "He is trying to increase his accuracy but not his precision"
Explanation:
right on EDGE 2021
(True/False) Solid Potassium Chloride, KCl (s), consists of equal numbers of positive Potassium ions (K+), and negative Chloride ions (Cl-) arranged in three dimensional networks called crystals. (6 Pts)
Answer:
true
Explanation:
What’s this called please help
Answer:
the answer is a linear
Explanation:
heres a graph different ones at this link
What are alkali metals
Answer:
Alkali metals are highly reactive elements that appear to be silver and they are found in group 1 of the periodic table. It consists of lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr). As you go further down the group, the more reactive they are. Those elements all react to water and air, so they must be kept in oil to preserve their state.
You are about to take a short trip. However, you will not be traveling by car or bus; instead you will be traveling up in a hot air balloon. You know that hot air balloons, like the ones pictured, are able to rise when the air contained in them is heated. Why does the balloon rise? What is happening at the molecular level to make the balloon rise?
Answer:
Hot air rises. Heated air molecules “spread out” or expand and bounce around, and the space becomes less dense than the surrounding space. Increasing the air temperature inside the balloon envelope makes it less dense than the air, thus making it “lighter than air”.
Explanation:
I'm new to brainly but I hope this helped!
Balloon rise because Warm air ascends. Heat causes the molecules of the air to "spread out," or expand, and bounce off one another, making the area less dense than the surroundings.
What are molecules ?
A molecule is the smallest unit of a substance that keeps its content and properties. It is made up of two or more atoms that are joined together by chemical bonds.
Chemistry is built on molecules. The element symbol and a subscript indicating the number of atoms are used to identify molecules.
When Balloon rise because Warm air ascends. Heat causes the molecules of the air to "spread out," or expand, and bounce off one another, making the area less dense than the surroundings.
The air inside the balloon's envelope becomes less dense as the temperature rises, making it "lighter than air."
To learn more about molecules, refer to the below link:
https://brainly.com/question/14130817
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10 POINTS
Which tool can be used to measure the volume of a liquid to one decimal place?
Options:
a beaker
a graduated cylinder
an Erlenmeyer flask
a test tube
Which is the IUPAC name for NO?
nitric oxide
binitrogen oxide
dinitrogen dioxide
nitrogen monoxide
The IUPAC name for NO is nitric oxide. The correct option is A.
What is IUPAC naming?The International Union of Pure and Applied Chemistry (IUPAC) is a global organization that represents chemistry as well as related sciences and technologies.
The chemical compound's identity is represented by its common and IUPAC names, which differ from one another. Every chemical compound has multiple names.
Complete the following step-by-step response: The IUPAC nomenclature is a standardized name given to organic compounds in accordance with official naming rules.
Nitric oxide, also known as NO, is a colorless gas. It is one of the most important nitrogen oxides.
Nitric oxide is a free radical, which means it has an unpaired electron, which is sometimes represented in its chemical formula by a dot.
Thus, the correct option is A.
For more details regarding IUPAC, visit:
https://brainly.com/question/16631447
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Answer:
D: Nitrogen Monoxide
Explanation:
There's one Nitrogen atom and one Oxygen atom
How do I put Chlorofluorocarbons in a sentence?
Answer: Here are some examples
Explanation:
1. In the southern spring, ozone is destroyed above Antarctica, mainly by manufactured compounds called chlorofluorocarbons (CFCs )
2. It is now generally accepted that the loss of stratospheric ozone is caused by chemical reactions initiated by chlorofluorocarbons.
3. Your refrigerator and other home appliances emit Chlorofluorocarbons, or CFCs, as do aerosol spray cans.
Hope this hlps!
Explanation:
To be able to put the chemical term chlorofluorocarbons in a sentence, you must first understand what the chemical species denotes.
We know chlorofluorocarbons are a group of compounds that consists of atoms of chlorine, flourine, and carbon.
Now, here are some sample sentences;
Chlorofluorocarbons are one of the leading causes of ozone depletion in the atmosphere. Most national governments are putting measures in place to check the use of chlorofluorocarbons in industrial manufacturing.If we can innovate a substitute for chlorofluorocarbons, the environment would be safer.What are natural resources
Answer:
resources that come from the ground or eath naturally which also means that those minerals like coal take hundreds of years to be created
Which of the following is NOT an example of a chemical change? *
O Corrosion
O Grinding
O Combustion
O Rust
HELP ASAPP JUST TELL ME WHAT TO PUT IN THE MISSING SPACES words(cell,microorganisms,micrometer,microscopic,molecule)
Answer:
microorganisms, molecule, microscopic, cell, micrometer
Explanation:
If you find my answer helpful
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The transition metals (with the exception of Zn, Cd and Hg) are very much hard and have low volatility. Why Zn ,Cd and Hg has low melting points. (a) These have all their electrons paired. (b) These have maximum number of unpaired electrons. (c) These have very strong metallic bonding. (d) These have more metal-metal bonding.
Answer:
Zn ,Cd and Hg has low melting points because - These have all their electrons paired.
Explanation:
These have all their electrons paired -: All the electrons in the d-subshell are combined with Zn , Cd and Hg. The metallic bonds present in them are, therefore, weak. This is why they have low points of melting and bolting. therefore , this statement is true. These have maximum number of unpaired electrons. Since , these transition metals have all electrons paired , so this statement is incorrect.These have very strong metallic bonding -: Zn, Cd and Hg d-orbital are completely filled. They have poor metallic bonding and less compact packing due to their fully filled d-orbitals, so all of them are volatile in nature. Therefore, this statement is also not valid .These have more metal-metal bonding. -: Since , their metallic bond is weak , so this statement is not true .Hence , the correct option is A (These have all their electrons paired).
an atomic mass unit is defined exactly as
Answer:Atomic mass is the mass of an atom in atomic mass units (amu)
Atomic mass
• atomic mass (sometimes called atomic weight) is the mass of the atom in atomic mass units (amu). (from periodic table)
o One atomic mass unit is defined as a mass exactly equal to one-twelfth the mass of one carbon-12 atom. Carbon-12 is the carbon isotope that has six protons and six neutrons. Setting the atomic mass of carbon-12 at 12 amu provides the standard for measuring the atomic mass of the other elements.
o For example, experiments have shown that, on average, a hydrogen atom
Find an element that has the same
number of valence electrons as
Thallium (T1).
i need the answer nowww
Answer:sodium
Explanation: because its not hard to look on the PERIODIC TABLE
True or false
Each family represents the number of energy levels present in an atom of the element.
Answer:
true because of the elements
8. Describe how crystals of copper sulphate are prepared.
Answer:
Take a cupful of water in a beaker and add a few drops of dilute sulphuric acid. Heat the water. When it starts boiling, add copper sulphate powder slowly while stirring continuously. ... Crystals of copper sulphate will be seen at the bottom of the beaker.
Hope it helps
the ability for a substance to rust is
a. oxidation
b.rustability
c.magnetic attraction
d.reactivity
Answer:
i think it is letter b. rustability but not so sureeee
What is Mercury's proximity to the sun
Answer:
46.943 million km
Explanation:
From an average distance of 36 million miles (58 million kilometers), Mercury is 0.4 astronomical units away from the Sun.
Answer:
29.169 million miles
Explanation:
From an average distance of 36 million miles(58 million kilometers,Mercury is 0.4 astronomical units away from the sun.
what turns colour in an acid and base
Answer:
Chemists use a solution called Universal Indicator to identify acids and bases. ... The Universal Indicator Color Guide shows that Universal Indicator turns red when it is added to a strong acid, it turns purple when it is added to a strong base, and it turns a yellowish-green when it is added to a neutral solution.
Explanation:
Answer:
Phenolphthalein
Explanation:
Describe how calcium and fluorine bond together to form calcium fluoride. The electron arrangement of each atom is shown.
Answer:
Detail is given below.
Explanation:
Calcium is alkaline earth metal. It has two valance electron. Thus calcium needs six more electron to complete the octet. Thus, its very easy for calcium to remove its two electron and get complete octet.
Electronic configuration of Ca:
Ca₂₀ = [Ar] 4s²
While,
Fluorine is halogen. It has seven valance electrons. It needed only one electron to complete the octet. When it combine with calcium , calcium loses two electrons thus two atom of fluorine combine with one atom of fluorine and stable compound calcium fluoride is formed.
Electronic configuration of F:
F₉ = [He] 2s² 2p⁵
Chemical equation:
Ca + F₂ → CaF₂
How would you arrange the objects below from greatest to least volume?
A balloon
A water bottle
A bottle of soda
A rock
Answer:
A balloon
A bottle of soda
A rock
A water bottle
Explanation:
Why is the nitrogen cycle considered a closed system?
Answer:
because nitrogen is fixed by bacteria and assimilated by plants
Explanation:
Answer:
It is a considered a closed system because nitrogen is fixed by bacteria and is taken in by plants.
Explanation:
Molecules in a liquid are:
closer together than in a gas
moving more quickly than in a solid
moving more slowly than in a gas
all of the above
Please help!!!
Answer:
all of the above
Explanation:
1. A pile of boxes exerts a force of 500 newtons downward on the floor. The boxes are not in motion. What is the normal force on these boxes?
2. Norman drags a stubborn dog by his leash with a force of 200 newtons. The dog is slowly moving towards Norman. What do you know about the force exerted by the dog?
3. A baby grand piano sits in a music room. The piano exerts a force of 3500 newtons downward. Isaac tells his friends that he is strong enough to lift the piano off the floor. How much force will he have to use to lift the piano?
4. Ms. Holt is dragging a box of assessments across the floor using a force of 70 newtons. The frictional force acting against the box is 50 newtons. What is the net force on the box?
5. A bicycle is sitting motionless in the driveway. What is the net force acting on this bike?
6. Maria drops a box that exerts of force of 300 newtons downward on a table. The normal force acting on the box from the table is 250 newtons. What will happen to the table and the box? What is the net force of the box?
7. Anna is riding her bike, moving at a constant velocity of 3 miles per hour to the south. She is using 200 N of force to pedal her bike. A gust of wind blowing in the same direction she is traveling suddenly exerts a force of 20 Newtons on her. What will happen to her motion? (hint: Use the term accelerate OR decelerate in your answer.)
8. Mrs. Fedde is riding her bike, moving at a constant velocity of 5 miles per hour to the north. She is using 300 N of force to pedal her bike. A gust of wind blowing in the opposite direction she is traveling suddenly exerts a force of 50 Newtons on her. What will happen to her motion? (hint: Use the term accelerate OR decelerate in your answer.)