Explanation:
At the upper left is the atomic number, or number of protons. In the middle is the letter symbol for the element (e.g., H). Below is the relative atomic mass, as calculated for the isotopes found naturally on Earth. At the very bottom is the name of the element (e.g., hydrogen).
the product of 13cm and 5.7cm is correctly reported as
a. 75cm^2
b. 74.0cm^2
c. 74 cm^2
d. 74.1 cm^2
Answer:
d] 74.1 cm²
Explanation:
Product means that the values given must be multiplied.
13 cm × 5.7 cm = 74.1 cm²
why is it dangerous to wear contact lenses in the lab
Answer:
It is strongly recommended that students do NOT wear contacts lenses in the laboratory. Chemical vapors may penetrate the contact lens material and cause the lens to adhere to one's eye, which could be detrimental to the eye. Goggles are not vapor tight and do not completely eliminate this absorption.
In a bond between silicon (Si) and chlorine (CI), (answer here) will be more electronegative. A. silicon B. chlorine
Answer:
Chlorine
Explanation:
Chlorine has a valence shell of 7 electrons and chlorine is smaller in size, so it has a stronger pull/attraction on the electrons than Silicon.
HELP!!!!
Which of the following has the smallest electron affinity?
а К
b Ca
C Li
d Na
e Mg
Answer:
e. Mg.
Explanation:
Answer:
[tex]mg[/tex]
is the answer to your question
match each statements with the state of matter it describes?
Answer:
Solid liquids , plasma gas
Explanation:
It retains its shape regardless of the shape of the container
In a laboratory, a student combines vinegar and baking soda into a beaker. The initial temperature is 28 degrees Celsius and the final temperature reading two minutes later is 20 degrees Celsius.
1. What happened to the heat in the surroundings?
2. Did an endothermic or exother mic reaction occur
The reaction is endothermic because the temperature dropped from 28 degrees Celsius to 20 degrees Celsius.
Meaning of endothermic and exothermic reaction:An endothermic reaction is one in which heat is absorbed from the surrounding resulting in decrease in temperature while an exothermic reaction is one in which heat is evolved causing the temperature to rise.
In the particular context of this question, the reaction is endothermic because the temperature dropped from 28 degrees Celsius to 20 degrees Celsius. The heat in the surroundings decreased.
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Calculating Heat during Phase Changes
question below in photo :)
Answer:
Q1= 9.42
Q2= 227 KJ
Q3= 31.4 KJ
Qt=269 KJ
Explanation:
First you have to find the heat needed to make ice at a temperature of -45 C to pass to a temperature of 0 C.
You're given the formula so all you have to do is replace by the data you're given (remember to make the Celsius, Kelvin by adding 273.15 to the Celsius since the magnitudes of temperature they're giving you in the constants are the Kelvin)
Q1= (2.093 J/gxK)(100 g)(45 K)
Q1=9418.5 J
Q1=9.4185 KJ≈9.42 Kj(you're asked to give your answer in KJ)
You know have to find the energy needed to liquify the ice, in other words you need to use the enthalpy of fusion to determine the energy that's being used, and since you have 100 grams of water, you only need to find the number of moles present in 100 grams of water by dividing the number of grams by the molar mass of water (18 g/mol) and then replace in the equation.
Q2=(5.56 mol)(40.7 KJ/mol)
Q2=227 KJ
You know have to find the energy needed to raise the temperature of water from 0 C to 75 C. You do the same thing as you did in the first step:
Q3=(4.184 J/gxK)(100 g/)(75K)
Q3=31380 J
Q3=31.38 KJ≈31.4 KJ
For the final step, you only add the Qs of each step:
9.42KJ+227KJ+31.4KJ= 267.82 KJ ≈ 267.8 KJ
Why do you use these procedures?
Well, you could simply have made a unique equation at first sight that involved the changes of temperature from -45 C to 75 C, but you have a phase change in the middle. Phase change keep temperature constant but they require heat from the surroundings in order to, in the case of ice, break the bonds that keep the molecules tight together.
This heat required from the surroundings is the Enthalpy of phase change, in this case enthalpy of fusion.
F
norm
app
F
grav
F
fric
Which statement is true in this situation?
A. The size of Ffric is the same as the size of Fgrav-
B. The size of Fnorm is the same as the size of Ffric
C. The size of Ffric is the same as the size of Fapp:
D. The size of F
app is the same as the size of Fgrav
The statement is true in this situation is C. The size of Ffric is the same as the size of Fapp:
From the diagram, since the body is in equilibrium, the sum of vertical forces equals zero. Also, the sum of horizontal forces equal zero.
So, ∑Fx = 0 and ∑Fy = 0
Since Fapp acts in the negative x - direction and Ffric acts in the positive x - direction,
∑Fx = -Fapp + Ffric = 0
-Fapp + Ffric = 0
Fapp = Ffric
Also, since Fgrav acts in the negative y - direction and Fnorm acts in the positive y - direction,
∑Fy = Fnorm + (-Fgrav) = 0
Fnorm - Fgrav = 0
Fnorm = Fgrav
So, we see that the size of Fapp equals size of Ffric and the size of Fnorm equals the size of Fgrav.
So, the correct option is C
The statement which is true in this situation is C. The size of Ffric is the same as the size of Fapp.
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The Statue of Liberty is composed of copper. The smallest particle of any amount of copper is A) an atom. B) an element. C) a compound. Eliminate D) a molecule.
an atom because its the smallest thing in the entire world and in all orgnaisms
The elements fluorine (F), chlorine (Cl), and Iodine are all part of the same ____________________ on the periodic table.
Question 9 options:
group
period
Answer:
Halogen Family of elements
Explanation:
Group Seventeen
Please help with the question in the picture!
Answer:
B. 1s,2s,2p,3s
Explanation:
What is Nuclear fusion
Answer:
Nuclear fusion is a reaction in which two or more atomic nuclei are combined to form one or more different atomic nuclei and subatomic particles (neutrons or protons).
Draw the Complete Electron Energy Level Diagram (or the Orbital Diagram) for Ru+3
Answer:
A
Explanation:
refer to textbook
If a sample of gas at constant temperature has its pressure doubled, what will happen to its volume?
Answer:
it'll halve
Explanation:
the gas is compressed with twice the pressure. The volume will be halved.
im certain
Pls Help Me (20 Points)
In one to two sentences, describe an experiment that would show that intramolecular forces (attractions between atoms within molecules) are stronger than intermolecular forces (attractions between molecules).
Answer:
If the molecules have similar molar masses and similar types of intermolecular forces, look for the one that is the most polar or that has the most electronegative atoms or the most hydrogen bonding groups. That one will have the strongest IMF's overall.
Explanation:
An experiment that would show that intramolecular forces are stronger than intermolecular forces will be heating a block of ice in a sealed container then allowing it to change to steam.
Intramolecular forces are the forces of attraction that hold atoms together within a molecule. Intramolecular forces require a high amount of energy to splits atoms or molecules in a chemical bonding.
Intermolecular forces are weaker forces of attraction that occur between molecules. They require lesser energy to splits molecules compared to intramolecular forces.
An experiment that show that intramolecular forces are stronger than intermolecular forces will be heating a block of ice in a sealed container then allowing it to change to steam.
In the process, the energy required to change the state from ice to steam water is more than intermolecular forces.
Thus, we can conclude that this experiment shows that the intramolecular forces are stronger than the intermolecular forces.
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PLEASE HELP ME ON THIS
Answer:
The conductance will increase as the concentration of the electrolyte is increased.
Explanation:
The ions are what carry the charges from one electrode to another. The more there are, the easier it is for electrons to get across the solution of electrolyte,
Why does potassium have a lower electronegativity than Bromine?
Potassium has a lower EN than Bromine.
EN Trends:
Decreases down the group but increases across a period.
Potassium is to the left of the periodic table while bromine is on the right, and according to the trends, Bromine will be bigger because EN increases across a period. This allows the nucleus to attract the bonding electrons more strongly.
Hope it helps!
how to tell if an electron will make a cation or anion
In chemistry class, you are given a density column with 3 liquids (shown in the
image). A small sample of beryllium (a metal) with a mass of 2.8 grams and a volume
of 1.5 mL is added to the column. Where would the metal sample be located in the
column?
Answer:
A)
Explanation:
the mass number of an element whose atoms contain 18 protons, 22 neutrons and 18 electrons
Answer:
Argon has the chemical formula Ar. Argon has 18 protons and 22 neutrons in its nucleus giving it an Atomic Number of 18 and an atomic mass of 40. Argon is a Noble Gas. Argon is a gas at room temperature.
Explanation:
Which models of the atom in task 1 are not supported by the results of the hydrogen gas experiment? For each of these models, explain the experimental results that the model would predict.
Answer:
Thomson placed two magnets on either side of the tube, and observed that this magnetic field also deflected the cathode ray. The results of these experiments helped Thomson determine the mass-to-charge ratio of the cathode ray particles, which led to a fascinating discovery, minus the mass of each particle was much, much smaller than that of any known atom. Thomson repeated his experiments using different metals as electrode materials, and found that the properties of the cathode ray remained constant no matter what cathode material they originated from. From this evidence, Thomson made the following conclusions:
The cathode ray is composed of negatively-charged particles.
The particles must exist as part of the atom, since the mass of each particle is only ~1/2000 the mass of a hydrogen atom.
These subatomic particles can be found within atoms of all elements.
While controversial at first, Thomson's discoveries were gradually accepted by scientists. Eventually, his cathode ray particles were given a more familiar name: electrons. The discovery of the electron disproved the part of Dalton's atomic theory that assumed atoms were indivisible. In order to account for the existence of the electrons, an entirely new atomic model was needed.
Explanation:
a sample osoxooso sixisoxoso
Answer:
I believe the correct answer is A.
Explanation:
He atoms are smaller than Ne atoms (4AMU vs 20AMU). Although the kinetic energy and concentrations are the same (same temperature and each have 0.5 mole in 10.0L containers), the kinetic energy is a product of mass and velocity. Since the Ne mass is greater, it will have a lower speed, thus taking longer to bounce out the pinhole.
Definition for starch in science ?
Answer:
Starch is a polysaccharide comprising glucose monomers joined in α 1,4 linkages. orStarch is a long-chain polymer of glucose molecules joined together. orA starch is a complex polysaccharide made up of a large number of glucose units joined together by glycosidic bonds.Explanation:
starch, a white, granular, organic chemical that is produced by all green plants. Starch is a soft, white, tasteless powder that is insoluble in cold water, alcohol, or other solvents.
Starch is amongst the most abundant plant products and is a mixture of two polymers, amylose and amylopectin. During food processing starch is transformed by hydrothermal treatments. ... The structure of starch is also influenced by specific and non-specific interactions with other food constituents and ingredients.
100 POINTS PLEASE HELP
1. What is the molar mass of NaOH?
2.How many atoms are in 3.35 moles of Aluminum?
3.How many moles of CO2 gas are in a 101.25 L container filled with CO2 gas?
4.What is the mass of 13.7 moles of N2 gas?
5.How many moles are in 78.5 molecules of CaCO3?
Answer:
1) Molar mass of NaOH can be calculated by taking the atomic mass values in the periodic table. Na (Sodium) = 22.98g/mol, O (Oxygen) = 16g/mol, H (Hydrogen) = 1.01g/mol
Add all the the mass values together for NaOH's molar mass, so (22.98 + 16 + 1.01) = 39.99 or round it to 40g/mol
2) To find the atoms from the moles, you just multiply Avogadro's number (6.02 x 10^23) by the moles.
So 3.35 x (6.02 x 10^23) = 2.0167 x 10^24 atoms are in 3.35 moles of aluminum
3) If the question is asking under standard temperature and pressure, we know that if we divide the volume by the molar volume of a gas (which is 22.7 in standard temperature and pressure), we can get the moles.
So 101.25L / 22.7 = 4.46 mol
4) We know that to find the moles, it is the mass divided by the molar mass. If we rearrange the equation to solve for mass, we have to multiply the moles by the molar mass to get there.
Nitrogen's (N) molar mass on the periodic table is 14g/mol, but since Nitrogen is a diatomic element, it would be N2 by itself. So multiply 14 by 2, which will give you 28g/mol. N2's molar mass is 28g/mol.
Now you multiply 13.7 moles by 28g/mol, which will give you 383.6g
5) Now here I think you may have wrote the question wrong. Molecules would be at a way higher number than just 78.5, so I'm first just going to assume you meant 78.5g.
To get the moles from mass, you divide the mass of the compound by its molar mass. Molar mass of CaCO3 can be just calculated using the atomic mass values for each element in the compound (Ca is 40.07g/mol, C is 14g/mol, O3 would be 16 x 3 g/mol or just 48g/mol) and then adding them all together (40.07 + 14 + 48 = 102.07) which would give us 102.7g/mol.
Now, just divide the mass 78.5g by the molar mass 102.7g/mol
78.5/102.7 = 0.764 moles
Now on the offchance that you were actually referring to molecules, and you accidentally typed a different number doing this, you can find out the moles from the molecules by just dividing the number of molecules you have with avogadro's number (6.02 x 10^23)
So it would look something like this:
molecules of CaCO3 / 6.02 x 10^23
Maximum s-character is observed in
a) Triple bonded carbon atom b) Double bonded carbon atom
c) Single bonded carbon atom d) Carbon atom of benzene
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Maximum s-character is observed ina) Triple bonded carbon atom b) Double bonded carbon atomc) Single bonded carbon atomd) Carbon atom of benzene[tex]\huge{\underline{\underline{\boxed{\sf{\red{Answer}}}}}}[/tex]
Maximum s-character is observed ina) Triple bonded carbon atomWrite the complete electron configuration using the diagonal rule for strontium.
Claim-Evidence-Reasoning
Question: Does the diagramed chemical equation above obey the Law of
Conservation of Matter?
Answer:
matter cannot be created or destroyed in chemical reactions. This is the law of conservation of mass. In every chemical reaction, the same mass of matter must end up in the products as started in the reactants. Balanced chemical equations show that mass is conserved in chemical reactions.
Explanation:
state one cause of temporary hardness of water
Answer:
Temporary hardness of water is caused when thermally unstable chemicals like magnesium hydrogen carbonate and calcium hydrogen carbonate are dissolved in water. Temporary hardness is treated by heating the hard water.
Hope that helps. x
most common elements that bond with oxygen
Explanation:
most common elements that bond with oxygen is Hydrogen (H2) to form water
After the first four games of a professional football season, three players scored a total of 80 touchdowns. Duke Johnson scored 14 of the touchdowns. Josh McCown scored 40% of the touchdowns. Andre Roberts scored the remaining touchdowns. How many touchdowns did Andre Roberts score?.
The number of touchdowns scored by Andre Roberts = 34 touchdowns
Given data :
Total number of touchdowns = 80
Number of players = 3
Determine the number of touchdowns scored by Andre RobertsPlayer 1 ( Duke Johnson ) scored = 14
Player 2 ( Josh McCown ) scored = 40% of 80 = 32
∴ number of touchdowns scored by player 3 ( Andre )
= 80 - ( 14 + 32 )
= 80 - 46 = 34 touchdowns
Hence we can conclude that the number of touchdowns scored by Andre is 34 .
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