An element is a substance that cannot be broken down by chemical means. Elements are extremely particular compounds that serve as the foundation for all life and matter (well other than the stuff smaller than atoms). It can contain one atom or trillions of them for anything to be an element, however atoms of different types cannot be combined in. That is to say, every atom has a set number of protons, ranging from 1 to 118. You can be positive that the substance you have is hydrogen if there is just one proton present. Mercury is what you get if you have 80 protons. Atoms of pure hydrogen only contain one proton. As most people are aware, if you add oxygen to it, it turns into water, which is no longer an element but a compound. Nevertheless, the building blocks are the elements. Every single object you can see is composed of elements, whether there are many of them, as there are in the human body, or only a few, as there are in salt.
A compound is a substance with a definite composition (with some leeway there, there are 'non-stoichiometric' compounds), that is composed of 2 or more elements.
Further explanation:
A compound in chemistry is a material that is created by mixing two or more distinct chemical elements in such a way that the atoms of the various elements are kept together by strong chemical bonds. These bonds form as a result of the sharing or exchange of electron s among the atoms. A molecule is the smallest, unbreakable unit of a substance.
A mixture is not a compound since there is no bonding between the atoms of the constituent substances in a mixture. In certain cases, mixing dissimilar elements causes chemical reactions that result in the formation of bonds between the atoms and the molecules of a compound. Other possibilities allow mixing distinct components without causing a reaction, preserving the separate identities of the elements. When elements are combined, reactions can happen quickly or slowly (for example, when iron is exposed to oxygen) (as when lithium is exposed to oxygen). There are times when an element is introduced to a chemical, a reaction takes place, creating new compounds (as when pure elemental sodium is immersed in liquid water).
A compound frequently looks and acts quite different from any of the constituent parts. Think about hydrogen (H) and oxygen, for instance (O). At standard atmospheric pressure and room temperature, both of these substances are gases. However, they combine to form the well-known material known as water, which is a liquid at room temperature and at normal atmospheric pressure and whose molecules each contain two hydrogen atoms and one oxygen atom (H2O).
Few elements' atoms readily combine with those of other elements to produce compounds. These gases—helium, neon, argon, krypton, xenon, and radon—are referred to as noble or inert gases. Compounds made of certain elements can be formed easily with other elements. Examples include fluorine, chlorine, and oxygen.
2) The adjective compound refers to something that is made up of several different components. Examples of this usage include compound eyes, which are found in a variety of insects, compound microscopes, which are high-power magnifying devices made up of multiple lenses, compound sentences, which are organized collections of smaller sentences that form a single integrated perceptual environment, and compound documents.
a)
Name the following compounds
CH, -CH-CH
(i)
CH, Br
-
Answer:
methyl, ethyl,
Explanation:
that should be the case
Which statement correctly describes the conductivity of the specified material?
Gold has a high conductivity
Most plastics have a high conductivity
Most wires are made to have a low conductivity
Copper has a low conductivity
Answer:
Gold has a high conductivity
Explanation:
This is because gold is a metal that occur free in nature in rocks, alluvial , grains e.t.c. it is a transition metal and in group 11 of the periodic table do it conduct electricity. It has has conductivity because it is a metals because all metals have ability to conduct electricity. When it is pure, it is a bright, slightly reddish yellow, . It is soft, malleable.
It is a ductile metal
and ductile metal.
Answer:GOLDDDDD
Explanation:
The eye can see colors because:
a. the cones in the retina send signals to the brain.
b. the rods in the cornea send signals to the brain.
c. the optic nerve determines the color of the object and sends signals to the brain
d. None of the choices are correct.
Answer:
The answer is A, I think.
Answer:
the answer is A
Explanation:
The human eye and brain together translate light into color. Light receptors within the eye transmit messages to the brain, which produces the familiar sensations of color. Newton observed that color is not inherent in objects. Rather, the surface of an object reflects some colors and absorbs all the others.
GIVING BRAINLIEST AND 20 POINTS
Which number represents precipitation on the hydrologic cycle diagram?
1
2
3
4
Answer:
Number three, because precipitation is rain, which comes from cumulonimbus clouds. Precipitation happens when clouds have accumulated enough evaporated water for the cloud to get heavy and need to get rid of some of the water, which it does through condensing the water and then delivering it as rain.
Hope this helps! Have a wonderful day! (Please give me brainliest and thank you!)
:)
WILL GIVE 10 PTS AND BRAINIEST FOR THE RIGHT ANSWER PLEASE HELP!!!
____ is important for making amino acids, proteins, and the chlorophyll a plant uses to carry out photosynthesis.
A. Boron
B. Nitrogen
C. Potassium
D. Phosphorus
E. Calcium
Answer:
c
Explanation:
structure of 2,6-diiodo-4-methyl-5-propylheptane
Explanation:
2,6-Dibromo-4-isopropylphenol
2432-16-8
2,6-dibromo-4-propan-2-ylphenol
Phenol, 2,6-dibromo-4-(1-methylethyl)-
4-isopropyl-2,6-dibromophenol
PLEASE HELP
MY PARENTS WILL KILL ME IF I DONT GET MY SCHOOL WORK DONE BY 12 PM TODAY!! AND I DONT UNDERSTAND IT!!
If the mass of an unknown object is 2 grams and the volume is 2.35 cubic centimeters, what is the density of that object?
a. _________________________
b. Look back at Table 4.1. Based on your calculated density, what is the substance? _________________________
Answer:
oh ok
Explanation:
importance of distillation column in industry
Answer:
Distillation columns are used to separate mixed feed streams into their own distinct products.
Explanation:
The primary function of the distillation column is to separate the feed stream into (at least) one highest level product stream and one bottom product stream. The performance of the column separation can be justified by the purity of the upper and lower product streams.
Convert 392 K into Celsius.
Your answer should have three significant figures (round your answer to the nearest whole number).
Use −273∘C for absolute zero.
Answer:
118.85 degrees celsius (not sure if it is)
Answer:
118 is correct
Explanation:
:)
How does a temperature increase cause the rate of a reaction to increase?
A. It increases the kinetic energy of the molecules.
B. It decreases orientation requirements of the molecules.
C. It increases the equilibrium constant for the reaction.
D. It decreases the activation energy of the reaction.
Answer:
B
Explanation:
"The temperature increases cause the rate of a reaction to increases the kinetic energy"
What is rate of reaction?
The reaction rate, also known as the rate of reaction, is the rate for which a chemical reaction occurs, and is proportional to increase in product concentration per unit time and the reduction in reactant concentration per unit time. The rate of reaction varies greatly.
What is kinetic energy?
An object's kinetic energy is the energy it has as a result of its motion. It is the amount of work required to push a body of a given mass from rest to a certain velocity. The body keeps its kinetic energy gained during acceleration unless that speed changes.
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Identify the acid,
Base and salt of following.
b) lime water
d) potassium oxide
coppor sulphate
( vinegar
Answer:
Lime water Ca(OH)2 is a base
Potassium oxide K2O is a basic oxide
Copper sulphate CuSO4 is a salt
And vinegar is an acid
Explanation:
Which unit is used for measuring atomic mass?
А.atomic mole
B. grams/mole
C. grams
D. atomic mass unit
E. atomic mass weight
how to rapidly separate red#40 from ZnO
Answer:
your question :how to rapidly separate red#40 from ZnO
answer :Red #40 is soluble in water while zinc oxide is not. 4- heat the solution of red #40 and water until water evaporates and red#40 remains
hope it's help
#carryONlearning4 moles of monoatomic ideal gas is compressed adiabatically causing the temperature to increase from 300 K to 400 K. Calculate the work done on the gas in units of Joules (if the answer is negative, be sure to enter a negative sign in your answer).
Answer:
the work done on the gas is 4,988.7 J.
Explanation:
Given;
number of moles of the monoatomic gas, n = 4 moles
initial temperature of the gas, T₁ = 300 K
final temperature of the gas, T₂ = 400 K
The work done on the gas is calculated as;
[tex]W = \Delta U = nC_v(T_2 -T_1)[/tex]
For monoatomic ideal gas: [tex]C_v = \frac{3}{2} R[/tex]
[tex]W = \frac{3}{2} R \times n(T_2-T_1)[/tex]
Where;
R is ideal gas constant = 8.3145 J/K.mol
[tex]W = \frac{3}{2} R \times n(T_2-T_1) \\\\W = \frac{3}{2} (8.3145) \times 4(400-300) \\\\W = \frac{3}{2} (8.3145) \times 4(100)\\\\W = 4,988.7 \ J[/tex]
Therefore, the work done on the gas is 4,988.7 J.
In the following reduction of iron ore, 3C + 2Fe2O3 –> 4Fe + 3C02, iron is reduced and _____ is oxidized.
A) carbon dioxide
B) carbon
C) iron oxide
D) oxygen
Answer:
B carbon
Explanation:
guessed
i don’t understand this please help!!!
Answer:
Numbers after atoms are subscripts. Numbers before atoms are coefficients.
Equation: 2Na +Cl2 -> 2NaCl
Given: 6.8 grams of Na
Unknown: moles of NaCl
Set up: [tex]6.8g Na *\frac{1 mole Na}{22.99 g Na}*\frac{2 moles NaCl}{2 moles Na} =.2957 moles NaCl[/tex]
Explanation:
We know that the reactants are Na and Cl and that what is being produced, the products, is NaCl.
Na + Cl -> NaCl
CAREFUL! Cl is a diatomic ion, is it gets a subscript of 2! This means there need to be 2 cl atoms on the right side as well. But now there are 2 Na on the right side. So we multiply Na by 2 on the left so that both sides have two Na atoms.
2Na +Cl2 -> 2NaCl
B)
We know that there are 6.8 grams of Na. This is our given.
What do we want to find out? We want to find how many moles of NaCl there are, so that is our unknown.
C) A mole ratio is exactly what it sounds like. From our balanced equation, we can see that there are 2 moles of Na and 2 moles of NaCl. In other words, there are 2 moles of Na for every 2 moles Nacl. In notation, this is [tex]\frac{2 mole Na}{2 Mole NaCl}[/tex] or 2:2. You can simplify to 1:1 ratio, but as equations get more complex I find it easier to not. It depends on what your teacher wants and what you find easier.
D)
By set up I assume they mean stoichiometry (chemistry conversion) . First I'm going to split up the set up so that it is easier to understand.
We start with the given and convert that into moles Na. We can do this by remembering that there are 22.99 grams for every 1 mole Na:
6.8 g Na* [tex]\frac{1 mole Na}{22.99g Na} = .2957 moles Na[/tex]
Now we can use that mole ration we found in part C to convert moles of Na into moles of NaCl:
[tex].2957 moles Na *\frac{2 moles NaCl}{2 moles Na}= .2957[/tex]
Usually, we will put these together to get
[tex]6.8g Na *\frac{1 mole Na}{22.99 g Na}*\frac{2 moles NaCl}{2 moles Na} =.2957 moles NaCl[/tex]
Tip: in Stoichiometry, it is important to remember that your units should cancel out until you only have the units you want. If there are moles of Na in the numerator, there should be moles of Na in the denominator of the following fraction. If there are grams Na in the numerator, there should be grams Na in the denominator and so and so on until you are only left with the unit you want, which, in this case, is moles of NaCl.
(feso4.(Nh4) So4. 6H2o) +Kmno4+H2So4_Fe2(So4)3+K2So4+mnSo4+(Nh4)2So4+H2o
Answer:
balancing the equation?
All of the following are physical changes except
A. ice melting.
B. plaster hardening.
C. paint drying.
D. rocket fuel burning.
Answer:
rocket fuel burning i think
26. Find the volume of 111.6 grams of NH3 gas.
Answer:
It is 148.82 L
Explanation:
I need more points. And I hope this helps.
A 51.1g sample of brass is put into a calorimeter (see sketch at right) that contains 250.0g of water. The brass sample starts off at 95.4°C and the temperature of the water starts off at 25.0°C. When the temperature of the water stops changing it's 26.4°C. The pressure remains constant at 1atm.
Required:
Calculate the specific heat capacity of brass according to this experiment.
Answer:
0.415 j/g°C
Explanation:
Given that :
Mass of water, m1= 250.0 g
Temperature of water, T1= 25°C
Specific heat capacity of water, C= 4.184 J/g°C
Mass of brass , m2= 51.1g
Temperature of brass = 95.4°C
Specific heat capacity of brass , c2=?
Final temperature = 26.4°C
Heat lost by brass = Heat gained by water
mc(dT) = mc(dT)
51.1 * c * (95.4 - 26.4) = 250 * 4.184 * (26.4 - 25)
51.1 * 69 * c = 250 * 4.184 * 1.4
3525.9c = 1464.4
c = 1464.4 / 3525.9
c = 0.4153265
c = 0.415 j/g°C
Specific heat capacity of Brass for the experiment = 0.415 j/g°C
Household hydrogen peroxide is an aqueous solution of hydrogen peroxide (H2O2), and its concentration is often measured as a percent by weight. Most drug stores sell 3% solution, which means there are 3.0 g of H2O2 per every 100 g total of solution (H2O2 H2O). For the kinetics experiment, 15 mL of 3% (w/w) hydrogen peroxide solution was poured into a measuring cup with 120 mL of water. 5 mL of 1M sodium carbonate solution (Na2CO3) was also added to the mixture. What is the molar concentration (molarity) of hydrogen peroxide (in mol/L) of the final solution
Answer:
0.093 M
Explanation:
First, we assume that the density of household hydrogen peroxide is 1 g/mL. We also assume that there's no reaction between hydrogen peroxide and sodium carbonate, if there were, in the end all hydrogen peroxide would be consumed.
Now we calculate how many grams of H₂O₂ were added, using the given volume, concentration and density:
15 mL * [tex]\frac{1gSolution}{1mL}*\frac{3gH_2O_2}{100gSolution}[/tex] = 0.45 g H₂O₂We convert grams to moles:
0.45 g H₂O₂ ÷ 34 g/mol = 0.013 mol H₂O₂
Now we divide the number of moles by the final volume, to calculate the molarity of H₂O₂:
Final Volume = 15 mL + 120 mL + 5 mL = 140 mL140 mL / 1000 = 0.140 LMolarity = 0.013 mol H₂O₂ / 0.140 L = 0.093 MBased on the given concentration of the original hydrogen peroxide solution, the molarity of the hydrogen peroxide (in mol/L) of the final solution is 0.093 M.
What is the concentration of the hydrogen peroxide solution?Assuming that the density of household hydrogen peroxide is 1 g/mL and that no reaction occurs between hydrogen peroxide and sodium carbonate.
The mass in grams of H₂O₂ added is first determined using the given volume, concentration and density:
mass = volume * density * concentrationmass = 15 mL * 1 g/mL * 3g/100g = 0.45 g H₂O₂
Moles of H₂O₂ is determined as follows:
moles = mass /molar massmolar mass of H₂O₂ = 34 g/mol
moles of H₂O₂ = 0.45 g H₂O₂ / 34 g/mol
moles of H₂O₂ = 0.013 mol H₂O₂
molarity of H₂O₂ is then calculated as follows:
molarity = moles/volume in Lfinal volume = 15 mL + 120 mL + 5 mL = 140 mL
final volume = 140 mL / 1000 = 0.140 L
molarity = 0.013 mol H₂O₂ / 0.140 L
molarity of H₂O₂ = 0.093 M
Therefore, the molarity of the hydrogen peroxide (in mol/L) of the final solution is 0.093 M.
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How many significant figures
are in this number?
5.67 x 10^2
Answer:
3
Step-by-step explanation:
Hence, the given number has 3 significant figures.
A gas occupies 135 cm3 at 143. K. At what Celsius temperature will its volume be 140 cm3? Assume that pressure remains constant.
Answer:
New temperature T2 = -124.7 °C
Explanation:
Given:
Old volume V1 = 135 cm³
New volume V2 = 140 cm³3
Old temperature T1 = 143 K
Find:
New temperature T2
Computation:
V1 / T1 = V2 / T2
135 / 143 = 140 / T2
New temperature T2 = 148.3 K
New temperature T2 = 148.3 - 273
New temperature T2 = -124.7 °C
A sample of polystyrene, which has a specific heat capacity of 1.880 J.g .°C , is put into a calorimeter (see sketch at right) that contains 300.0 g of water. The polystyrene sample starts off at 94.9 °C and the temperature of the water starts off at 22.0 When the temperature of the water stops changing it's 27.7 °C. The pressure remains constant at 1 atm. Calculate the mass of the polystyrene sample.
Answer:
56.6g
Explanation:
Given that :
Mass of water, m1= 300.0 g
Temperature of water, T1= 22°C
Specific heat capacity of water, C= 4.184 J/g°C
Mass of polystyrene, m2=?
Temperature of polystyrene = 94.9
Specific heat capacity of polystyrene, c2= 1.88 J/g°C
Final temperature = 27.7 oC
Heat lost by polystyrene = Heat gained by water
mc(dT) = mc(dT)
m2 * 1.88 * (94.9 - 27.7) = 300 * 4.184 * (27.7 - 22)
m2 * 1.88*67.2 = 300*4.184*5.7
126.336 * m2 = 7154.64
m2 = 7154.64 / 126.336
m2 = 56.631838
Hence, mass of polystyrene = 56.6g
Pleaseee I need help and it is urgent
Answer:
1)4180j
2)15000kj
Explanation:
[tex]1) E=100*(30-20)*4.18=4180j\\2)Q=.5*30*1000=15000kj[/tex]
1. 1 N2+ 3 H2→2 NH3
c.How many moles of nitrogen are needed to produce 12 moles of nitrogen trihydride?
[tex]\displaystyle 6 \ mol \ N_2[/tex]
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
BracketsParenthesisExponentsMultiplicationDivisionAdditionSubtractionLeft to RightChemistry
Atomic Structure
Writing CompoundsStoichiometry
Using Dimensional AnalysisReactions RxNExplanation:Step 1: Define
[RxN - Balanced] N₂ + 3H₂ → 2NH₃
[Given] 12 mol NH₃
[Solve] x mol N₂
Step 2: Identify Conversions
[RxN] 1 mol N₂ → 2 mol NH₃
Step 3: Stoich
[DA] Set up: [tex]\displaystyle 12 \ mol \ NH_3(\frac{1 \ mol \ N_2}{2 \ mol \ NH_3})[/tex][DA] Multiply/Divide [Cancel out units]: [tex]\displaystyle 6 \ mol \ N_2[/tex]Answer:
[tex]\boxed {\boxed {\sf 6 \ moles \ of \ N_2}}[/tex]
Explanation:
1. Balance Equation
We are given the reaction:
[tex]1 N_2+3H_2 \rightarrow 2 NH_3[/tex]
The equation is already balanced. Both sides have 2 moles of nitrogen and 6 moles of hydrogen.
2. Conversions
In this reaction, 1 mole of nitrogen produces 2 moles of nitrogen tryhdride:
[tex]1 \ mol \ N_2 \rightarrow 2 \ mol \ NH_3[/tex]
3. Stoichiometry Calculations
Use the conversion rate as a fraction.
[tex]\frac{ 1 \ mol \ N_2}{2 \ mol \ NH_3}[/tex]
Multiply the number of moles of nitrogen trihydride produced: 12 moles.
[tex]12 \ mol \ NH_3 *\frac{ 1 \ mol \ N_2}{2 \ mol \ NH_3}[/tex]
The moles of nitrogen trihydride cancel.
[tex]12 *\frac{ 1 \ mol \ N_2}{2} = \frac{ 12 \ mol \ N_2}{2}[/tex]
[tex]6 \ mol \ N_2[/tex]
6 moles of nitrogen are needed to produce 12 moles of nitrogen trihydride.
What do scientists use to answer scientific questions?
A. A scientific guidebook
B. The scientific method
C. A scientific law
D. The atomic theory
Scientists uses scientific methods and well designed experiments to solve a scientific question. They can use some laws and previous scientific records as an aid.
What is a scientific question ?A scientific question arises from selected topic under study. A scientific question addresses a natural phenomenon, a socially relevant problem or a any personal curiosity.
The scientific question must be testable. The first prediction for the question based on observation and scientific records is called the hypothesis.
The hypothesis must be tested using a well designed scientific experiment based on a scientific method. The methodology should be clearly specify what to collect and how to use them. Hence, option B is correct.
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What type of changes would you expect as you go down from the ocean's surface to
its bottom?
1.Temperature, pressure, light, and density all decrease
2.Temperature and pressure increase; light and density decrease
3.Temperature and light decrease; pressure and density increase
4.Temperature and density decrease; light and pressure increase
Answer:
answer is the 4th one
Explanation:
The type of changes one might expect as one goes down from the ocean's surface to its bottom is that temperature and light decrease; pressure and density increase.
What is pressure?Pressure is defined as the force applied on an object perpendicular to it's surface per unit area over which it is distributed.Gauge pressure is a pressure which is related with the ambient pressure.
There are various units by which pressure is expressed most of which are derived units which are obtained from unit of force divided by unit of area . The SI unit of pressure is pascal .
It is a scalar quantity which is related to the vector area element with a normal force acting on it.It is distributed over solid boundaries and across arbitary sections of fluid normal to the boundaries at every point.
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You have two compounds that you have spotted on a TLC plate. One compound is more polar than the other. You run the TLC plate with neat hexanes and find that only one spot moved a small distance up the plate. Next you made a 50/50 mixture of hexanes and ethyl acetate. What might you expect to see on your TLC plate (what would the spots do)?
Answer:
The two spots will move up the plate.
Explanation:
We have to first understand the rudiments of chromatography. In chromatography, there is a stationary phase and a mobile phase. The stationary phase does not move. In this case, the stationary phase is the TLC plate.
The mobile phase is the solvent used to perform the chromatography. The movement of the spots depends on the composition of the solvent.
When neat hexane was used, only one spot was moved. This must be due to the interaction of the nonpolar hexane with the less polar compound. However, when a 50/50 mixture of hexanes and ethyl acetate is used, the both compounds are found to move up the plate.
How many moles are there in 7.24 grams of calcium carbonate? With work shown
Answer:
0.0723371390261859