Answer:
Composting, recycling, technological development, water cycle and photosynthesis are changes that have good effects. Some changes have bad effect like pollution and destruction of habitat and lose of lives.
Explanation:
hope it helps
perform the converters
a) 32gr C2H4-in liters
b) 7,5 litera N2- in molecules
c) 1.4•10 ² ³ molecules CH4- in atoms
Answer:
the answers are given in the photo
SEP Construct Explanations You can see a cloud of your breath outside
on a cold day but not on a warm day. What do you think is happening to
pour breath in the cold air
Answer:
it because of cold weather
How can you tell the difference between two clear liquids
Answer:
To identify a pure liquid substance using the physical properties of solubility, density, and boiling point. The physical properties of a pure substance can be measured without changing the composition of the substance.
Explanation:
Iridium crystallizes in a face-centered cubic unit cell that has an edge length of 3.833 Å.
(a) Calculate the atomic radius of an iridium atom.
(b) Calculate the density of iridium metal
a.
The atomic radius of iridium is 1.355 Å
For a face-centered cubic unit cell, with edge length, a and atomic radius r,
we have a² + a² = (4r)²
2a² = 16r²
r² = a²/8
r = a/√8
Since a = 3.833 Å,
Substituting this into the equation, we have
r = a/√8
r = 3.833 Å/√8
r = 3.833 Å/2.828
r = 1.355 Å
So, the atomic radius of iridium is 1.355 Å
b.
The density of iridium metal is 22.67 g/cm³
To find the density of the iridium metal, we need to find the mass of atoms per unit cell.
So, for the face centered cubic iridium atom, there are 6 faces per unit cell × 1/2 atoms per face + 4 corners per unit cell × 1/4 atoms per corner = 3 atoms + 1 atom = 4 atoms per unit cell.
So, the mass of the atoms in the unit cell is m = number of atoms/cell × number of moles/atom × molar mass of Iridium
= 4 atoms/cell × 1 mol/6.022 × 10²³ atoms × 192.22 g/mol
= 768.88/6.022 × 10²³ g/cell
= 127.68 × 10⁻²³ g/cell
= 1.2768 × 10⁻²¹ g/cell
Next, we need to find the volume of the unit cell which is V = a³
= (3.833 Å)³
= (3.833 × 10⁻¹⁰ m)³
= 56.314 × 10⁻³⁰ m
= 5.6314 × 10⁻²⁹ m
So, the density of iridium = mass of unit cell/volume of unit cell
= m/V
= 1.2768 × 10⁻²¹ g/cell ÷ 5.6314 × 10⁻²⁹ m
= 0.2267 × 10⁸ g/m³
= 0.2267 × 10⁸ g/m³ × 10⁻⁶ m³/cm³
= 0.2267 × 10² g/cm³
= 22.67 g/cm³
So, the density of iridium metal is 22.67 g/cm³
Learn more about face-centered cubic unit cell here:
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As atoms get smaller,valance electrons are getting closer or farther away from the nucleous.The force of attraction is stronger o weaker so it takes more or lesss energy to remove electrons?
Explanation:
Electrons are closer to the nucleus are in filled orbitals and are called core electrons. More energy which in nucleus called nuclear strOng energy to remove electron thars why its also a way harder too..
Which of the following is true of grinding during
digestion?
A. The process of grinding is a physical change
that takes place in the mouth during digestion.
B. The process of grinding is a chemical change
that takes place in the mouth during digestion.
C. The process of grinding is a physical change
that takes place in the small intestine during
digestion
D. The process of grinding is a chemical change
that takes place in the small intestine during
digestion
The process of grinding is a physical change that takes place in the mouth during digestion.
GRINDING:Grinding is one of the processes that occur during the digestion of food molecules into simpler substances.
Grinding of food molecules occurs in the mouth with the aid of the teeth, which is used to chew.
However, the process of grinding is a physical change because it does not result into the formation of new substances or change the chemical constituents of the food.
Learn more about physical change at: https://brainly.com/question/1984022?referrer=searchResults
HELP ME PZLMSMS
E
D
D
F
F
Answer:
10.C
11.B
15.A
Explanation:
the high electrical conductivity of metals is primarily due to
High conductivity of metals is caused by electrons that are free to move through the lattice.
hope this helps!
In an investigation that uses the scientific method, which step immediately follows making a hypothesis?
summarizing the results
asking a question
making observations
designing an experiment
C????
Answer:
The answer is designing an experiment
Explanation:
Since we already have a hypothesis, we need to test the hypothesis and this is done by designing an experiment that will do this test.
If a sample of air in a school container was heated, would the percentage of oxygen in the air increase, decrease, or remain unchanged?
Answer:
increase
Explanation:
Let's suppose we have a sample of air in a closed container. We heat the container and we want to predict what would happen to the pressure.
According to Gay-Lussac's law, the pressure of a gas is directly proportional to its absolute temperature.
Thus, if we increased the temperature of the air by heating it, its pressure would increase.
If a sample of air in a closed container was heated, the total pressure of the air would increase.
Nitrogen and oxygen can be separated from liquid air.State the name of this process.
Explanation:
Because of the earth and climate change the point of incidence mean that you mean by engineers to social evils activities.
How many grams of LiF would need to be dissolved to make 400 mL of a 1.67 M solution?
Group of answer choices
30 g LiF
20 g LiF
10 g LiF
40 g LiF
Answer:
20g
Explanation:
hope helpful.............
Which two elements are found in significant amounts (1% or more) in both the Universe and the human body?
Answer:
hydrogen and helium is the answer.
should i tell my parents i got C+ in chemistry or not ?
how many moles of oxygen molecule is reacting with sodium according to the following reaction:
2Na+O - Na2O2
1 mole of oxygen.
Answer:
solution given:
[tex]2Na+O_2=Na_2O_2\\2mole\:\: 1mole \:\: 1mole[/tex]
according to the above reaction,1 mole of oxygen is required to react with 2 moles of sodium to form sodium peroxide.
Explanation:
Almost 99% of the Earth's atmosphere is made up of two gases. What ere the two gases and the percents of each?
Answer:
21% oxygen and 78%nitrogen
Explanation:
Answer:
Nitrogen and Oxygen
Explanation:
nitrogen - 78 %
oxygen - 21%
How many atoms of carbon are present in 4.10 moles??!
Answer:
2.4×1024 atoms.
Explanation:
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Exhaling CO2 (Carbon Dioxide) is an example of what?
A-Excretion
B-movement
C- Nutrition
D- Reproduction
50 POINTS PLEASE HELPP
Circle the compound that has the higher boiling point and explain why we see the
differences we do
Answer:
1. Ethane has a higher boiling point
2. Heptyne has a higher boiling point
3. Octane has a higher boiling point
Explanation:
1. Ethane has stronger intermolecular attractions (van der Waal's forces) than ethene and so has the higher boiling point.
2. The longer (and the straighter) the chain, the greater the opportunity for intermolecular interactions, and thus the greater the boiling point. You should look up these boilig points! n-Pentane has a normal boiling point of approx. 36 ∘C ; n-heptane boils at 98 ∘C .
3. Octane has a high boiling point, because its molecule contains 8 Carbon atoms, and with increasing molecular weight of hydrocarbon its boiling temperature increases.
express in word equation and chemical equation of the chemical reaction when potassium chlorate is heated.
Answer:
Word equation: Potassium chlorate → Potassium chloride + Oxygen
Chemical equation: KClO₃ → KCl + O₂
Explanation:
This is decomposition reaction so there will only be one reactant, which is potassium chlorate.
The chemical equation will be:
KClO₃ → KCl + O₂
The balanced equation would be:
2KClO₃ → 2KCl + 3O₂
The word equation will be:
Potassium chlorate → Potassium chloride + Oxygen
1. Have scientists been able to invent a perpetual motion machine?
O Yes
O No
Identify the total number of molecules in the chemical formula: 6CH4 a 6 b 10 c 24 d 30
Answer: A.6
Explanation:
The total number of molecules in the chemical formula is 6
What is a molecule?
Molecules are the smallest particle of a substance that has all of the physical and chemical properties of that substance. Molecules are made up of one or more atoms.
The correct form of question will be:-6 molecule of methane CH₄
6CH4
a) 6 c) 10 c) 24 d) 30⇒ Number of aton of carbon is 6
⇒Number of atom of hydrogen is 24
⇒Total number of atom is 30
What is an atom ?
An atom is a particle of matter that neither be created nor be destroyed. An atom consists of a central nucleus that is usually surrounded by one or more electrons. Each electron is negatively charged. The nucleus is positively charged, and contains one or more relatively heavy particles known as protons and neutrons.
Learn more about molecules here: https://brainly.com/question/26044300
#SPJ2
what is the number of the atom in 1 mole of methanol CHɜOH ?
What is the mass number (A) of an atom that has an atomic number (Z=26) with 29 neutrons and 26 electrons?
Answer:
A = 55
Explanation:
The atomic number is the number of protons also = the number of electrons, so basically we have 29 neutrons, 26 electrons and 26 protons. Anyway, it's asking the mass number which is the neutrons + the protons, so you just take 29+26 = 55
Atomic number=26
Neutrons=29
Electrons=26
Mass number=Proton+neutron
Protons=26
Mass number=26+29
=55
Pick the odd one out
Paraffin wax
Hexane
Ethanol
Carbon tetrachloride
Answer:
Ethanol is the odd one.....
How can one determine if a compound is ionic or covalent?
Answer:
If a compound is made from a metal and a non-metal, its bonding will be ionic. If a compound is made from two non-metals, its bonding will be covalent.
Which of the following statements is true about atomic spectra? I. The line spectra of elements are evidence that electron energies are quantized II. Energy is emitted from atoms as they move from lower energy levels to higher energy levels III. Energy is emitted from atoms as they move from higher energy levels to lower energy levels IV. Neutral atoms in the ground state emit light spontaneously
The line spectra of an atom offers conclusive evidence that electron energies are quantized.
Neils Bohr showed that electrons in an atom can absorb or emit energy when they move from one energy level to another. This principle is the basis upon which the spectra of atoms is built.
The true statements about the atomic spectra is;
The line spectra of elements are evidence that electron energies are quantized Energy is emitted from atoms as they move from higher energy levels to lower energy levelsLearn more about atomic spectrum: https://brainly.com/question/2049494
a ___ wave is a disturbance in matter that transfers energy through the matter.
Answer:
Mechanical Waves
50 POINTS PLEASE HELP
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?
Answer:
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
Just did a few edits here, 4.46 for question 3 is in moles not L
Taking into account the definition of avogadro's number,
2. 3.35 moles of aluminum contains 2.018ײ⁴ atoms.
3. 4.52 moles of CO₂ gas are in a 101.25 L container filled with CO₂ gas.
4. 13.7 moles of N₂ contain 383.6 grams.
2. How many atoms are in 3.35 moles of Aluminum?
Avogadro's Number is called the number of particles that make up a substance (usually atoms or molecules) and that can be found in the amount of one mole of said substance. Its value is 6.023×10²³ particles per mole. Avogadro's number applies to any substance.
Then you can apply the following rule of three: if 1 mole of aluminum contains 6.023×10²³ atoms, then 3.35 moles of aluminum contains how many atoms?
amount of atoms of aluminum= (6.023×10²³ atoms × 3.35 moles)÷ 1 mole
amount of atoms of aluminum=2.018ײ⁴ atoms
Finally, 3.35 moles of aluminum contains 2.018ײ⁴ atoms.
3.How many moles of CO₂ gas are in a 101.25 L container filled with CO₂ gas?The STP conditions refer to the standard temperature and pressure. Pressure values at 1 atmosphere and temperature at 0 ° C are used and are reference values for gases. And in these conditions 1 mole of any gas occupies an approximate volume of 22.4 liters.
Then, you can apply the following rule of three: If by definition of the STP conditions 1 mole of CO₂ occupies a volume of 22.4 L, how many moles does 101.25 L occupy?
[tex]amount of moles of CO_{2} =\frac{101.25 Lx1 mole of CO_{2} }{22.4 L}[/tex]
amount of moles of CO₂= 4.52 moles
4.52 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?The molar mass of substance is a property defined as its mass per unit quantity of substance, in other words, molar mass is the amount of mass that a substance contains in one mole.
In this case, the molar mass of N₂ is 28 g/mole. So, you can apply the following rule of three: If 1 mole of N₂ contains 28 grams, 13.7 moles of N₂ contain how much mass?
[tex]mass=\frac{13.7 moles x28 grams}{1 mole}[/tex]
mass= 383.6 grams
13.7 moles of N₂ contain 383.6 grams.
Learn more about
Avogadro's Number: brainly.com/question/11907018?referrer=searchResults brainly.com/question/1445383?referrer=searchResults brainly.com/question/1528951?referrer=searchResultsSTP conditions:brainly.com/question/3773297?referrer=searchResults brainly.com/question/9901446?referrer=searchResults brainly.com/question/12695086?referrer=searchResults brainly.com/question/15507610?referrer=searchResults brainly.com/question/14260169?referrer=searchResults brainly.com/question/14831640?referrer=searchResultsmolar mass:https://brainly.com/question/1145279pleaseee PLEASEEE PLEASEEE I NEED HELPPP!!
can someone do these for me I will give brainliest