Answer: 4 atoms.
Explanation:
What is the concentration of H3O+ ions in saliva if [OH-] = 4.22 x 10-10 M? Provide the pH and the classification of this sample of saliva.
pH=4.625
The classification of this sample of saliva : acid
Further explanationThe water equilibrium constant (Kw) is the product of concentration
the ions:
Kw = [H₃O⁺] [OH⁻]
Kw value at 25° C = 10⁻¹⁴
It is known [OH-] = 4.22 x 10⁻¹⁰ M
then the concentration of H₃O⁺:
[tex]\tt 10^{-14}=4.22\times 10^{-10}\times [H_3O^+]\\\\(H_3O^+]=\dfrac{10^{-14}}{4.22\times 10^{-10}}=2.37\times 10^{-5}[/tex]
pH=-log[H₃O⁺][tex]\tt pH=5-log~2.37=4.625[/tex]
Saliva⇒acid(pH<7)
Will give brainliest!!!
How is coal formed?
Answer:
Coal is formed when dead plant matter submerged in swamp environments is subjected to the geological forces of heat and pressure over hundreds of millions of years. Over time, the plant matter transforms from moist, low-carbon peat, to coal, an energy- and carbon-dense black or brownish-black sedimentary rock.
explain why solid sodium chloride does not conduct electricity
Answer:
It does not contain free mobile ions
Explanation:
Solid sodium chloride does not conduct electricity because it does not contain free mobile ions.
Although sodium chloride is an ionic compound, in solid state, there is absence of free mobile ions. In aqueous solutions or in molten form, ionic compounds can conduct an electric current using free mobile ions as carriers. Therefore, they are electrolytes.In solid state ions are arranged into crystal lattice and will not conduct a current of electricity.
compare and contrast a Covalent and an ionic bond
Which of the following is a trait of group 18 (column 18)?
they are all stable metals
They are chemically stable gasses
They are all reactive
metals
They are a mix of reactive gasses and solids
Answer: They are chemically stable gases
Explanation:
Group 18 is also called the noble gases - because they have full valence shells it means they are stable and won't chemically react.
Prokaryotic cells and Eukaryotic cells both contain all 4 biomolecules. True or False
What type of kinetic energy is a rainbow?
Neutrons released in a fission reaction can strike other nuclei and cause
Answer:
Chain reaction
Explanation:
Which of the following landforms (physical features) was formed when two landmasses collided?
Hawaiian Islands
Mariana Trench
Himalayan Mountains
I need help plz Its a simple middle school question on science about energy PLZZZ I need help
Answer:
I believe C
Explanation:
The absence of air between the two forms a vacuum seal which preserves the contents inside. I think that's right... good luck :)
i need help on question 3 true or false thxxx quick i’m timed
Answer:
The answer is true.
What is the wavelength of gamma ray electromagnetic radiation with a frequency of 2.73x10^20 Hz?
Answer:
1.10 × 10⁻¹² m
General Formulas and Concepts:
Chemistry - Atomic Structure
Speed of Light = Wavelength times Frequency
c = λν c = 3.0 × 10⁸ m/sExplanation:
Step 1: Define
ν = 2.73 × 10²⁰ Hz
Step 2: Find wavelength
3.0 × 10⁸ m/s = λ(2.73 × 10²⁰ Hz)
λ = 1.0989 × 10⁻¹² m
Step 3: Check
We are given 3 sig figs. Follow sig fig rules.
1.0989 × 10⁻¹² m ≈ 1.10 × 10⁻¹² m
How is the process of using patterns to predict phases of the moon similar to the process Mendeleev used to predict undiscovered elements?
The characteristic of some repeating property can be used to find the answer is
The periodic table and the moon phases can be ordered according to some repeating property, you can create an ordered table and leave the gaps for the unknown properties.
The periodic table created by Mendeleev was initially based on the atomic weight of the elements, but he realized that the similarities of the atoms were greater if he used the atomic number, so he changed the ordering.
Mendeleev found that elements with the same number of electrons in their last shell had similar properties, when he ordered them he found that there were holes in the table, shortly after the work of many researchers the holes were completed and found numerous new chemical elements.
In the observation of the phases of the Moon around the earth it is found that for short measurements there are four phases, for longer measurements in addition to these four phases there are several higher repetition periods, with repeated observation the phases and periods are found. .
We can see that the two jobs are searched for, which is repeated and a table is created, leaving the spaces that are not known empty, with subsequent jobs filling these holes.
In conclusion, with the characteristics of some repeating property, the answer can be found is
The periodic table and the phases of the moon can be ordered according to some repeating property, you can create an ordered table and leave the gaps for the unknown properties.
Learn more about the periodic table here:
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what are units of molarity
Answer:The units of molarity are M or mol/L. A 1 M solution is said to be “one molar.”
Explanation:
Answer:
mol/L
Explanation:
Someone please help!!
Balances these redox equations
Cr2O7^2-(aq)+ I-(aq)-> Cr^3+(aq)+ I2(s)
Which element has four energy levels?
cesium (Cs)
rubidium (Rb)
potassium (K)
sodium (Na)
Answer:
Potassium (K)
Explanation:
Out of the four options, Potassium is the only one to fill a total of 4 energy levels.
Both Cesium (Cs) and Rubidium (Rb) fill more than three energy levels, with Cesium filling 6 and Rubidium filling 5.
Sodium (Na) only fills 3 energy levels.
Thus, that leaves Potassium (K), which has 4 energy levels.
Hope this helped ^-^
Which one of these have the biggest ionization energy and why? O, N, F
Answer: Fluorine has the highest ionization enthalpy.
Explanation: This is because the ionization energy decreases from top to bottom and increases from left to right. Also, ionization enthalpy is the amount of energy required by an isolated gaseous atom to lose an electron in its ground state.
Since fluorine needs just one atom to attain noble gas configuration so it will not want to lose any electron and hence a high amount of energy will be required to remove an electron from it.
Select all that apply.
How would you compare Venus's rotation to Earth's rotation?
Venus's rotation is backward compared to Earth's.
Venus's rotation is the opposite compared to Earth's.
Venus's rotation is retrograde compared to Earth's.
Venus's rotation is the same compared to Earth's.
I need answers ASAP
Answer:
backward, opposite, retrograde
Explanation:
why, i just got it right when i put that.
Answer:
here they are
Explanation:
Venus's rotation is backward compared to Earth's.
Venus's rotation is the opposite compared to Earth's.
Venus's rotation is retrograde compared to Earth's.
The electron that is located in the outermost shell of the octet rule.
Answer:
im not sure what answer you're looking for here, their called valence electrons if thats what you're looking for.
Explanation:
If you have 1.26 x 10^24 molecules, how many moles do you have?
Answer:
E
Explanation:
Just e
1)26.4 % Carbon
3.3 % Hydrogen
70.3 % Oxygen
Molar Mass: 91.0 g/mol
Empirical Formula:
Molecular Formula:
Answer:
1. Empirical formula => CH2O2
2. Molecular formula => C2H4O4
Explanation:
From the question given above, the following data were obtained:
Carbon (C) = 26.4 %
Hydrogen (H) = 3.3 %
Oxygen (O) = 70.3 %
Molar mass of compound = 91.0 g/mol
Empirical formula =..?
Molecular formula =..?
1. Determination of the empirical formula of the compound.
C = 26.4 %
H = 3.3 %
O = 70.3 %
Divide by their molar mass
C = 26.4 /12 = 2.2
H = 3.3 /1 = 3.3
O = 70.3 /16 = 4.39
Divide by the smallest
C = 2.2 /2.2 = 1
H = 3.3 /2.2 = 2
O = 4.39 /2.2 = 2
Empirical formula => CH2O2
2. Determination of the molecular formula of the compound.
Molar mass of compound = 91.0 g/mol
Empirical formula => CH2O2
Molecular formula => [CH2O2]n
We shall determine the value of n as follow:
[CH2O2]n = 91
[12 + (2×1) + (2×16)]n = 91
[12 + 2 + 32]n = 91
46n = 91
Divide both side by 46
n = 91/46
n = 2
Molecular formula => [CH2O2]n
Molecular formula => C2H4O4
In the given case where 26.4 % Carbon , 3.3 % Hydrogen , 70.3 % Oxygen , and Molar Mass: 91.0 g/mol the:
Empirical Formula: [tex]C_2H_3O_4[/tex] Molecular Formula: ([tex]C_2H_3O_4[/tex])[tex]_1[/tex]Given:
Carbon (C) = 26.4 %
Hydrogen (H) = 3.3 %
Oxygen (O) = 70.3 %
Molar mass of compound = 91.0 g/mol
Determination of the empirical formula of the compound:-
Divide by their molar mass for obtaining moles: C = 26.4 /12 = 2.2 H = 3.3 /1 = 3.3 O = 70.3 /16 = 4.39 for ratio Divide by the smallest: C = 2.2 /2.2 = 1 H = 3.3 /2.2 = 1.5 O = 4.39 /2.2 = 2
The ratio is CHO = 1 : 1.5 : 2
multiply with 2 to find correct and complete number ratio
C = 1 × 2 = 2
H = 1.5 × 2 = 3
O = 2 × 2 = 4
Thus, the Empirical formula => [tex]C_2H_3O_4[/tex]
Mass × n = molar mass
12 × 2 + 1 × 3 + 16 × 4 = 91
24 + 3 + 64 = 91
91 = 91
Thus moles are 1 which means
molecular formula = ([tex]C_2H_3O_4[/tex])[tex]_1[/tex]
Thus, here in the given data:
Empirical Formula: [tex]C_2H_3O_4[/tex]Molecular Formula: ([tex]C_2H_3O_4[/tex])[tex]_1[/tex]
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For the following elements, calculate the average atomic mass. Carbon-12
98.93%, Carbon-13 1.07% *
Answer:
Average atomic mass of carbon = 12.01 amu
Explanation:
Given data:
Average atomic mass = ?
Percent abundance of C-12 = 98.93%
Percent abundance of C-13 = 1.07%
Solution:
Average atomic mass of carbon = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass) / 100
Average atomic mass of carbon = (98.93×12)+(1.07×13) /100
Average atomic mass of carbon= 1187.16 + 13.91 / 100
Average atomic mass of carbon = 1201.07/ 100
Average atomic mass of carbon = 12.01 amu
10.0 gram sample of H20(l) at 23.0°C absorbs. 209 joules of heat. What is the final temperature of H20(l) sample?
Situation- I took time away from preparing for my Quiz competition to help two of my neighbourhood friends for their class exam. However, when I needed some help with my Science survey, none of them volunteered. I felt hurt and disappointed.
Response
a)No.3
b)No.5
c)No.1
d)No.4
Explanation:
canot understand the question
What are some chemical changes in oxygen?
the oxidation reaction between oxygen and sodium produces sodium oxide. In many cases, an element may form more than one oxide.
Explanation:
Use context clues to determine whether the bolded word in each sentence has a positive or negative connotation.
It’s fun to hang out with Serena
because she’s always
laid-back and relaxed.
Seth is so chatty that he won’t
even listen to what anyone
else has to say.
Michaela is so modest, she
never brags about her
accomplishments.
My brother is stingy because
he refuses to share anything
with me.
Desmond’s witty stories made us
laugh all night long.
Answer:
Answer:
1. Positive
2. Negative
3. Positive
4. Negative
5 positive
Explanation: I did this test before
The words have a positive, negative, positive, negative, positive connotation respectively in each of the given sentence.
What is connotation?
Connotation is defined as a property of a particular word or name which describes the ideas or qualities of the word.It is rather being named explicitly or described.
It is frequently described as a positive or negative connotation which is in connection with its pleasing or displeasing connection. Connotation can have words with literal meaning with what they specifically denote.
There are two types of connotations positive connotation and negative connotation wherein positive connotation has positive impact while negative connotation has negative impact.It describes the primary word and it is not necessary that it be present in the sentence or phrase.
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I need help ASAP... look at the picture:)
Answer:
its definitely A
Explanation:
hope this helps
A chemical change always involves...
A. a color change
B. a change in shape
C. the state of matter changing
D. a new substance forming
A geologist is making observations from atop a small mountain. She sees two parallel faults: one directly to the east and one directly to the west. She concludes that these faults are caused by tension stretching the crust. From what type of land feature is the geologist making her observations? plateau anticline syncline fault-block mountain
Answer: fault-block mountain
Explanation:
I got it right on edgen 2020
Answer:
d fault-block mountain
Explanation:
which wind belt do we live in
Answer:
the wind belt one
Explanation:
mhm
Answer:The USA lives in the Westerly Windbelt
Explanation: