why do atmospheric carbon dioxide levels fluctuate during the year?
Answer: The amount of CO2 found in the atmosphere varies over the course of a year. Much of this variation happens because of the role of plants in the carbon cycle
what is the function of the lungs
Answer:
the lungs are part of the respiratory system
Explanation:
Allows you to talk and to smell
Oxygen to the cells in your body
and helps you breathe
Answer:
Your lungs are part of the respiratory system, a group of organs and tissues that work together to help you breathe. The respiratory system's main job is to move fresh air into your body while removing waste gases.
Explanation:
Main functions of the lungs : -
Inhalation and Exhalation Are Pulmonary Ventilation - That’s Breathing External Respiration Exchanges Gases Between the Lungs and the Bloodstream.Internal Respiration Exchanges Gases Between the Bloodstream and Body TissuesAir Vibrating the Vocal Cords Creates SoundOlfaction, or Smelling, Is a Chemical SensationWhat is a chemical bond?
A. An intramolecular force holding 2 atoms together
B. An attractive force between 2 molecules
C. A gravitational force holding electrons in their orbits
D. An electrostatic force between a proton and an electron
A chemical bond is an electrostatic force between a proton and an electron. Hence, option D is correct.
What is a bond?A chemical bond is what holds atoms together in molecules.
A chemical bond is what holds atoms together in molecules.
Bonds arise from the electrostatic forces between positively charged atomic nuclei and negatively charged electrons (the positions of which in space are determined by quantum mechanics).
Hence, option D is correct.
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What are the features that allow you to identify an ionic compound based on its chemical formula
Answer:
first identify the cation and write down its symbol and charge. Then, identify the anion and write down its symbol and charge.
Explanation:
Explain The element lithium has two common isotopes: Li–6 and Li–7 If the average atomic mass of lithium is 6.94004 u, determine its percent isotopic step by step please urgently
Answer:
%Li-6 = 5.996% & %Li-7 = 94.004%
Explanation:
let X₁ = Li-6 & X₂ = Li-7 where Xₙ = mole fraction
X₁ + X₂ = 1 => X₁ = 1 - X₂
6·X₁ + 7·X₂ = 6.94004
=> 6(1 - X₂) + 7·X₂ = 6.94004
=> 6 - 6·X₂ + 7·X₂ = 6.94004
=> 6 + X₂ = 6.94004
X₂ = 6.94004 - 6 = 0.94004 => %X₂ = %Li-7 = 94.004%
X₁ = 1.00000 - 0.94004 = 0.05996 => %X₁ = %Li-6 = 5.996%
Students in class argue about whether salt (NaCl) or water (H2O) has stronger intramolecular forces. Which argument is BEST?
Question 3 options:
Water because it is a common material and will have stronger intramolecular force.
Water is attracted to salt and salt dissociates, so water has stronger intramolecular forces.
Salt never melted and water has a lower boiling point, so salt has stronger intramolecular forces.
Salt is a solid and water is a liquid, so water has stronger intramolecular forces.
Since intermolecular forces is stronger in a solid than a liquid, then NaCl has stronger intermolecular forces than H2O.
Intermolecular forces exists between molecules of the same or different kinds. Water has a dipole moment hence it can interact effectively with the ions in NaCl. This leads to an ion dipole interaction that results in the dissolution of NaCl in H2O.
NaCl is a solid and water is a liquid. Since intermolecular forces is stronger in a solid than a liquid, then NaCl has stronger intermolecular forces than H2O.
Hence, the best argument that compares the intermolecular interactions in water and NaCl is; salt is a solid and water is a liquid, so water has stronger intramolecular forces.
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How many grams of sodium hydroxide are present in 250.0 mL of a 0.300 M NaOH solution?
mixture requires constant shaking to keep its constituents combined. It is best described as a _____.
homogenous mixture
colloid
suspension
solution
Answer:
[tex] \tiny \tt \: [/tex]
Suspension
Which of the following best describes the relationship between a
mutation and a resulting change in the coat color of a mouse?
Answer:
A I think
Explanation:
what are colloids ?
A solution in which the size of solute particles is intermediate between those in true solution and suspension is called as Colloids.
Answer: A colloid is a mixture in which one substance consisting of microscopically dispersed insoluble particles is suspended throughout another substance.
Hope it helps , have a nice day :>
Antoine Lavoisier was able to show that mass wasn't lost or destroyed during chemical reactions by weighing all of the matter in the system before and after reactions occurred. What questions would you ask Lavoisier about how he conducted his investigations?
Answer: we can ask simple qs like was it a fair experiment and what he was actually looking for. Other qs include his variables use and that how he has maintained the experiment. Finally we could ask him for his outcome and what it would ahve changed in the near future
Explanation:
Which of the following requires the most input of energy?
Ovaporizing a substance
O melting a substance
O decreasing the temperature of the substance by 1°C
O raising the temperature of the substance by 1°C
Answer:
D ✔✔✔✔✔✔✔✔✔✔✔✔✔✔✔✔✔✔✔✔✔✔✔
What is responsible for the unusual chemical properties of water?
Answer:
hydrogen bonds
Explanation:
pls choose it as brianliest
The unusual chemical properties of water is due to its polar covalent bond.
What is polar covalent bond ?When atoms with differing electronegativities are shared between two atoms in such a covalent link, the result would be a polar covalent bond.
What is water ?Water is a kind of mixture of hydrogen and oxygen . Its chemical formula will be [tex]H_{2}O[/tex].
Along with its polar covalent connections, water displays a variety of interesting features. Because oxygen has a higher electronegativity than hydrogen, electron pairs were drawn closer to the oxygen atom, causing it to be partially negatively charged. As a result, both hydrogen atoms acquire a slightly positive charge.
Therefore, polar covalent bond will be responsible for unusual chemical properties of water.
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Which describes a molecule? (Select all that apply.)
It can be two or more different elements combined.
It can be two or more of the same elements combined together.
It can be one element by itself.
It can be the combination of different neutrons.
Answer:
All of them
Explanation: A molecule can be all of them
Question 1 (4 points)
Using the 4 pictures below, write a lab safety rule that could go with EACH of the pictures. You should have 4 rules in total (one for each picture)
[tex]▪▪▪▪▪▪▪▪▪▪▪▪▪ {\huge\mathfrak{Answer}}▪▪▪▪▪▪▪▪▪▪▪▪▪▪[/tex]
Blank # 1 - keep safe distance from the burner
Blank # 2 - Place the equipments on the right place after use
Blank # 3 - perform experiments with proper lab equipment and safety tools
Blank # 4 - Don't break any test tube or lab equipment
(maybe it can be hazardous)
Why is fluorine more reactive than and bromine
Answer:
- The Valence/Bonding Electrons (whatever name you address them as) in Flourine are closer to the nucleus than the Valence/Bonding Electrons are in an atom of Bromine.
Explanation:
Hopefully this was helpful!
A compound is 2. 00% H by mass, 32. 7% S by mass, and 65. 3% O by mass. What is its empirical formula? The first step is to calculate the mass of each element in a 100-g sample of the compound. We use 100 g because it makes the calculations more straightforward. What is the mass of each element in a 100. 0-g sample of the compound? mass H = g mass S = g mass O = g.
Answer:
We assume that there is 100g of the compound (because it makes it easier to calculate) and we turn the percentages into grams.
2% of Hydrogen = 2g of H
32.7% of Sulfur = 32.7g of S
65.3% of Oxygen = 65.3g of O
Now we change the mass of these elements to moles by dividing the mass by the molar mass (which is the value of atomic mass on your periodic table)
2g/1.01g = 1.98 mol
32.7g/32.06g = 1.02 mol
65.3g/16g =4.08 mol
divide all these mol values by the smallest mol value, which is 1.02. (Round the values to whole numbers)
1.98/1.02 = 2 (rounded) of Hydrogen
1.02/1.02 = 1 of Sulfur
4.08/1.02 = 4 of Oxygen
H2SO4 (also known as sulphuric acid) is your empirical formula.
How many electrons are there in the N shell of an element?
[tex] \huge \mathbb \pink{ANSWER:}[/tex]
2,5 the elctrons arw there in the N shell of an element.Explanation:
Hope it helps ^•^
Each shell can contain only a fixed number of electrons: The first shell can hold up to two electrons, the second shell can hold up to eight (2 + 6) electrons, the third shell can hold up to 18 (2 + 6 + 10) and so on. The general formula is that the nth shell can in principle hold up to 2(n2) electrons
20. At STP, an element that is a solid and a
good conductor of heat and electricity
could have an electron configuration of
(1) 2-7
(2) 2-8-8
(3) 2-8-5
(4) 2-8-18-2
20
Answer:
4
Explanation:
Zinc
Does this reaction meet the Law of Conservation of Mass? 2H2 + O2 → 2H2O explain.
Answer:
yes because on the left side 4 hydrogen in right side 4 hydrogen on the left side 2 oxygen in the right side 2 oxygen
Answer:
The Law of Conservation of Mass states that the mass of the system must remain constant over time as the system's mass cannot change because energy is not created nor destroyed. To tell if a chemical equation meets this law, check to see if the number of atoms is the same on both sides of the chemical equation.
Reactant Side:
4 atoms of Hydrogen2 atoms of OxygenProduct Side:
4 atom of Hydrogen2 atoms of oxygen.Remember, when counting the atoms in a equation the subscript is the number that represents the quantity of that specific atom. Subscripts are numbers that come after a symbol and below. If an element does not have a subscript, then it is understood that the subscript is 1. The coefficent represents the quantity of molecules, the coefficient multiplies everything in the formula.
How does One determine number of electron domains in molecul or ion
Answer:
The number of electron domains in a molecule or ion is the number of bonds (double and triple bonds count as one domain) plus the number of nonbonding (lone) electron pairs.
Explanation:
___is a measure of the change in velocity of a
moving object.
THIS IS URGENT ! Please fill in the blank
what are sources of error for a simple distillation lab?
Answer:
the fractions obtained are not of acceptable purity
Explanation:
what year did ernest rutherford make his discovery
Answer:
May, 1911: Rutherford and the Discovery of the Atomic Nucleus.
Explanation:
Mark me brainly please.
Someone pls help I have no clue what I’m doing
How many atoms of each element are in the compound AgNO3? (Hint: Ag is the
symbol for silver, N is the symbol for nitrogen, and O is the symbol for oxygen.)
1 silver, 1 nitrogen and 3 oxygen
Subscripts show the number of atoms of each element in a compound
There is no subscript after Ag which shows there is only one silver atom. There is no subscript after N which shows there is only one nitrogen atom. However, there is a 3 in the subscript after O which shows there are 3 oxygen atoms
1. What are five examples of observable properties?
anyone have any ideas on what i should draw for my art project please let me know
Answer:
A pumpkin or a deer cus it's hunting season
Birds, Scenerys, Fish, Planets, Seas, Trees, Butterflys, BTS, Fruits, Cactus! Drawing Ideas: Imagination
Draw an object and give it a face.
Create an alternate cover to your favorite book or album.
Illustrate a scene from your favorite song.
Draw a scene or character from your favorite book.
Illustrate your favorite fairy-tale.
Invent your own insects.
Draw an intricate made up flower.
Hope this helps!
Which processes could the heating curve be describing? Check all that apply.
boiling
condensation
endothermic reaction
exothermic reaction
freezing
Answer: condensation, exothermic reaction, freezing
Explanation: Edge
The heating curve could describe processes such as boiling, condensation and freezing.
What is a heating curve?A heating curve is a plot or graph wherein a substance is subjected to increasing temperature against time to measure the amount of energy it absorbs and changes state with increasing temperature.
Which processes could the heating curve be describing?
boiling. Yes, since matter goes from liquid to gas.condensation. Yes, since matter goes from gas to liquid.endothermic reaction. No, since phase changes are physical changes.exothermic reaction. No, since phase changes are physical changes.freezing. Yes, since matter goes from liquid to solid.The heating curve could describe processes such as boiling, condensation and freezing.
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how many of the following elements have 2 unpaired electrons in the ground state?
Answer:
I'll h he d Glendale https hehe
Explanation:
grendel v BB hehe iron v
if the column of water in the water barometer rose to a height of 39 feet, what would the atmospheric pressure be in mm hg?
The atmospheric pressure for a column of water barometer that rose to 39 feet is 874 mmHg
From the given information, to determine the atmospheric pressure at which the column of the water barometer rose, we will need to convert the height of the water column to mmHg.
From the dimensional analysis of standard rate conversion, we know that:
1 feet = 12 inches
1 inch = 25.4 mm
1 mmHg = 13.6 mm of water.
∴
[tex]\mathbf{\implies 39 \ feet \ of \ H_2O \times \dfrac{12 \ in ch \ H_2O}{1 \ feet \ H_2O} \times \dfrac{25.4 \ mm \ H_2O}{1 \ inch \ H_2O} \times \dfrac{1 mmHg}{13.6 \ mm \ H_2O}}[/tex]
= 874.058 mmHg
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