Answer:1
Explanation: friction is showing us how in the past
PLEASE HELP TIMED !!
question 1- draw a lewis dot diagram of O on a piece of paper. how many total electrons did you draw?
question 2- draw a lewis dot diagram of O on a piece of paper. how many Pairs of electrons did you draw?
question 3- draw a lewis dot diagram of Cl on a piece of paper. how many total electrons did you draw?
Answer:
See explanation
Explanation:
The Lewis dot structure is a representation of atoms in which the valence electrons on the atoms are shown as dots. Each dot represents a valence electron on the outermost shell of the atom.
Oxygen has six electrons on its outermost shell four of which are two lone pairs. Also, chlorine has seven electrons in its outermost shell. Six of these are lone pairs.
Brenda rode a skateboard 95 meters west. It took her 20 seconds. What was
her velocity?
A. 75 m/s west
B. 18 m/s west
C. 0.21 m/s west
D. 4.75 m/s west
SUBMIT
Answer:
D. 4.75 m/s west
Explanation:
You can immediately get the answer once you know the formula for velocity.
The formula for velocity is: Velocity (V) = [tex]\frac{distance (d)}{time (t)}[/tex]The distance is 95 meters while the time is 20 seconds. All you have to do is to divide 95 meters by 20 seconds.
Let's solve:
V = [tex]\frac{d}{t}[/tex]V = [tex]\frac{95 meters}{20 seconds}[/tex]V = 4.75 meters per secondSince Brenda is going west with her her skateboard, then you have to add west as her direction.
Brenda's velocity is 4.75 m/s west.
Two or more different elements chemically combined
Answer:
This question lacks some parts, it should read "Two or more different elements chemically combined make up a"
The answer is a COMPOUND
Explanation:
A compound is a type of pure substance that is formed as a result of the chemical combination of two or more different elements. During this combination, the atoms of the constituent elements are chemically joined together by CHEMICAL BONDS.
An example of a compound is CaCO3, which contains the following elements: Calcium, Carbon and Oxygen. In this compound, the atoms of the above listed elements are joined together by chemical bonds to form a COMPOUND.
5. If it's winter in the northern hemisphere, what season is it in southern
hemisphere?
Answer:
summer
Explanation:
Because the opposite of winter is summer (warm, hot)
who created The Big Bang Theory
State the relationship between phase changes and heat energy.
In complete sentences
Answer:
heat changes energy is by the sun
the sun gives off energy
What would happen if we did not have an atmosphere?
Answer:
The air would still be too thin to breathe. The lack of atmosphere would chill the Earth's surface. Organisms that need air to breathe would die.
Explanation:
Hope it helped!
More accurate dates of the reigns of ancient Egyptian pharaohs have been determined recently using plants
that were preserved in their tombs. Samples of seeds and plant matter from King Tutankhamun’s tomb have
a C-14 decay rate of 9.07 disintegrations/min/g of C. How long ago did King Tut’s reign come to an end?
Please show how to achieve the answer. I do not know how to get the answer of 3350 years. Please explain what equations
King Tut's reign came to an end at 3350 years ago
Further explanationCarbon-14 is a radioactive isotope that can decay. This isotope can be used to determine how long ago an organism died by knowing the ratio from 12C to 14C
Can be formulated
[tex]\tt Nt=No\dfrac{1}{2}^{t/t1/2}[/tex]
Or we can use :
[tex]t=-\frac{1}{\lambda }\text{ln}\left(\frac{{N}_{t}}{{N}_{0}}\right)\longrightarrow t=-\frac{1}{\lambda }\text{ln}\left(\frac{{\text{Rate}}_{t}}{{\text{Rate}}_{0}}\right)[/tex]
The half-life of C-14, 5730 years, so the decay constant :
[tex]\tt \lambda =\dfrac{\text{ln 2}}{{t}_{1\text{/}2}}=\dfrac{0.693}{\text{5730 y}}=1.21\times {10}^{-4}}[/tex]
Assume the initial C-14 activity was 13.6 disintegrations/min/g of C
[tex]\tt t=-\dfrac{1}{\lambda }\text{ln}\left(\dfrac{{\text{Rate}}_{t}}{{\text{Rate}}_{0}}\right)=-\dfrac{1}{1.21\times {10}^{-4}}\text{ln}\left(\dfrac{9.07}{13.6}\right)=\text{3348}\approx 3350~y[/tex]
How many calories are required to heat 10 ml of water from -5 to 25 0C?
a. 110 cal.
b. 0.48 cal.
c. 300 cal.
d. 2.1 cal.
Answer:
c. 300 cal
Explanation:
To calculate the heat, we use the following equation:
heat = m x Cp x ΔT
Where m is the mass of water, Cp is the specific heat of water (which is 1 cal/g.°C) and ΔT is the change in temperature (calculated as the difference between the final T and the initial T).
We have the volume of water (10 ml) but not the mass. As the density of water is 1 g/ml, the mass of water is:
density = mass/volume ⇒ mass = density x volume = 1 g/ml x 10 ml = 10 g
The change in temperature (ΔT) is:
ΔT= Final T - Initial T = 25°C - (-5°C) = 30°C
Finally, we introduce the data to calculate the heat:
heat = 10 g x 1 cal/g.°C x 30°C = 300 cal
Therefore, the correct option is c. 300 cal
A solution of potassium sulfate dissolved in 750 g of phenol boils at 183.5 degrees Celsius. What is the molal concentration of the solution. Phenol boils at 181.8 degrees Celsius.
A. 0.48 m
B.0.34 m
C.0.21 m
D.0.16 m
Answer:
D.
Explanation:
Yan Lang po Alam ko
Speed of an object at one instant of time is the object's_____ speed.
Answer:
Instantaneous Speed
Explanation:
forgive me if its wrong
HF(aq) and Ba(OH)2(aq) Express your answer as a balanced chemical equation. Identify all of the phases in your answer.
Answer:
[tex]2HF(aq)+Ba(OH)_2(aq)\rightarrow BaF_2(s)+H_2O(l)[/tex]
Explanation:
Hello!
In this case, since the neutralization reaction between hydrofluoric acid and barium hydroxide (both aqueous) produce insoluble barium fluoride and liquid water, we can write the chemical reaction as follows:
[tex]HF(aq)+Ba(OH)_2(aq)\rightarrow BaF_2(s)+H_2O(l)[/tex]
However, it needs to be balanced as hydrogen and fluorine are not properly balanced, therefore, we obtain:
[tex]2HF(aq)+Ba(OH)_2(aq)\rightarrow BaF_2(s)+H_2O(l)[/tex]
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yo please help. There is an image PLEASE... HELP... MEEEEE
Answer:
9. B different sounds the dog is exposed to
10. control, dependent, control, control, independent
Explanation:
What is the molecular geometry of CO2?
Answer:
Tetrahedral
And can u give me the brainlist I only need one to get a higher rank and thank u
Which of the following choices about teenagers and sex is true?
a. Over half of teenagers have sexual intercourse.
b. Teenagers who have sexual intercourse are more likely to use protection.
c. Teenage sex is more likely to involve coercion.
d. All of the choices are correct.
Answer:
D
Explanation:
.........................
sodium atoms differ from sodium ions in that sodium atom contains
1. one less proton
2. one less proton
3. one more electron
4. one less electron
Explanation:
sodium atom is neutral while sodium ion is a charged specie with a charge of +1
What's the theoretical yield if 5.50 g.of Hydrogen react with nitrogen to from amonia? 3H2+N2=2NH3
The theoretical yield : 31.11 g
Further explanationGiven
Reaction
3H2+N2=2NH3
Required
the theoretical yield
Solution
mol of Hydrogen :mol = mass : Ar
mol = 5.5 g : 2
mol = 2.75
mol of Ammonia :From the equation, mol ratio of H₂ : NH₃ = 3 : 2, so mol NH₃ =
[tex]\tt \dfrac{2}{3}\times 2.75=1.83[/tex]
Mass Ammonia (MW=17 g/mol):mass =mol x MW
mass = 1.83 x 17
mass= 31.11 g
what are all the products of a hydrocarbon combustion reaction
Answer: carbon dioxide and water
Explanation: hydrocarbons are compounds of carbon and hydrogen. Combustion is another word for oxidation. Oxygen splits, the CH bonds, oxidising both the C and the H. The simplest hydrocarbons, the alkanes, have the general formula C(n)H(n+2)
The combustion reaction is
(3n+1)O2 + 2C(n)H(2n+2) —> 2nCO2 + (2n+2)H2O
The products of a complete combustion reaction of a hydrocarbon in the presence of sufficient oxygen are carbon dioxide ([tex]CO_2[/tex]) and water ([tex]H_2O[/tex]).
Carbon dioxide and water are the end products of a hydrocarbon's full combustion reaction when there is enough oxygen present. The general equation: can be used to express this reaction.
Hydrocarbon + Oxygen -> Carbon Dioxide + Water
For example, if we consider the combustion of methane ([tex]CH_4[/tex]), the equation would be:
[tex]CH_4 + 2O_2 - > CO_2 + 2H_2O[/tex]
Here, one molecule of methane reacts with two molecules of oxygen to produce one molecule of carbon dioxide and two molecules of water.
Thus, the specific products of a hydrocarbon combustion reaction depend on the hydrocarbon being burned.
For more details regarding combustion, visit:
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Which radioactive element is used to determine the absolute age of Holocene animal remains? why?
pleaseeeeeeee help!!!
Carbon-14 dating radioactive element is used to determine the absolute age of Holocene animal remains .
What do you mean by radioactive element ?A radioactive element is one with an unstable nucleus, which radiates alpha, beta or gamma radiation and gets converted to a stable element.
Radioactive elements are unstable isotopes that release subatomic particles or energy as they decay.
Carbon-14 dating -
Carbon 14 dating, also defined as radiocarbon dating, is a method of determining age .
It is used to determine the age of everything from bones and plant fibers, to wood and pollen.
Hence the radioactive element Carbon-14 dating is used to determine the absolute age of Holocene animal remains .
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What is an example
Of a compound that contains a fluorine. Write the symbols for the chemical formula, and give the name.
Answer:
NaF sodium flouride
Explanation:
Write the formula for Carbon Trioxide
Answer:
Chemical Formula: Fe2O3.
Explanation:
Iron(III) oxide, ferric iron, hematite, red iron oxide, synthetic maghemite, colcothar, or simply rust—is one of the several oxide compounds of iron, and has paramagnetic properties
The formula for Carbon Trioxide is CO₃.
In Carbon Trioxide (CO₃), one carbon atom is bonded to three oxygen atoms. The subscript "3" indicates that there are three oxygen atoms in the molecule.
Carbon trioxide (CO₃) is not a stable molecule, and it does not exist as a discrete compound. The actual chemical formula for this compound does not represent a real chemical species.
Carbon trioxide was once proposed as a hypothetical compound with a triangular cyclic structure containing one carbon atom and three oxygen atoms. However, further research and experiments have shown that this structure is not viable due to the instability and high reactivity of such a compound.
Learn more about Carbon Trioxide from the link given below.
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A sample of water is cooled from 45°C to 35°C by the removal of 84 Joules of heat. What is
the mass of the water?
Answer:
m = 2 g
Explanation:
Given data:
Initial temperature = 45°C
Final temperature = 35°C
Heat evolved = 84 j
Mass of water = ?
Solution:
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
specific heat capacity of water is 4.18 J/g.°C
ΔT = 35°C - 45°C
ΔT = - 10°C
84 j = m ×4.18 J/g.°C ×- 10°C
84 j = m × -41.8 J/g
m = 84 j / -41.8 J/g
m = 2 g
negative sign shows heat is evolved.
Loren is examining a hair found at a crime scene. He notes radical changes in the coloring of the hair. What is the term for this type of coloring?
Answer:
Granules of the hair cortex.
Explanation:
hope it helpfully...Answer:
It is banding for plato / edmentum
Explanation:
I took notes in the class and in my notes it says -
Human hairs have consistent coloring, whereas animal hair coloring may change radically. This radical change is called banding.
Identify an element on the periodic table that is chemically similar to neon(Ne).
ANSWER
Elements that are similar to neon is helium, and argon
Hope its right if not so advance sorry :)
Answer:
He
Explanation:
plato
Pl help it’s for homwork
How does removing thermal energy from liquid water affect the molecules in the water?
Answer:
For deposition to happen, thermal energy must be removed from the gas. ... As water vapor loses thermal energy, it changes into solid frost. States of Water. Water is the only substance that exists naturally as a solid, a liquid, and a gas within Earth's temperature range.
Explanation:
How many grams of hydrogen gas would be required to produce 100.0 g H2O
Explanation:
11.11 grams of hysrogen is requited to make 100 g of water
in which way does a balanced chemical equation demonstrate the conservation of matter?
Answer:
Every chemical equation adheres to the law of every conservation of mass and the states of matter cannot be created or destroyed
Explanation:
) Calculate the pH of a polyprotic acid given and sketch the titration curves for the following reactions: (a) A 20.0-mL aliquot of 0.100M arsenic acid, H3AsO4, with 0.100M NaOH
Answer:
Following are the solution to the given question:
Explanation:
Let us indicate H3AsO4, an H3A triprotic acid; the ionising equations are as follows:
[tex]\to H_3A \Leftrightarrow H^+ + H_2A^- \\\\[/tex]
[tex]\to Ka_1 = \frac{[H^+][H_2A^-]}{[H_3A]}[/tex]
[tex]= 10-2.2 = 6.31 \times 10^{-3} \ \ \ \ \ \ \ \ [since\ pKa_1 = 2.2\ and \ Ka = -\log_{10}(pKa)]\\[/tex]
[tex]\to H_2A^{-} \Leftrightarrow H^{+} + HA_2^{-}; \\[/tex]
[tex]\to Ka_2 = \frac{[H^+][HA_2^-]}{[H_2A^-]} = 10-6.8 = 1.58 \times 10^{-7} \\(since pKa2 = 6.8)\\\\\to HA_2^- \Leftrightarrow H^+ + A_3^- ;\\\\ \to Ka_3 = \frac{[H^+][A_3^-]}{[HA_2^-]} = 10-11.6 = 2.51 \times 10^{-12} \\ (given pKa_3 = 11.6)[/tex]
The initial pH; we've 0.00 mL of 0.100 M NaOH – H3A is the main species; Ka1>>Ka2>>Ka3 is also noted. They therefore ignore H2A's disconnection but set up next ICE chart.
[tex]\to H_3A \Leftrightarrow H^+ + H_2A^- \\\\[/tex]
[tex]initial \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 0.100 \ \ \ \ \ \ \ \ \ \ \ \ \ \ 0 \ \ \ \ \ \ \ \ \ \ \ \ \ \ 0 \\\\[/tex]
[tex]change \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ - x \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ + x \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ + x\\\\equilibrium \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ (0.100 - x) \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ x \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ x\\\\[/tex]
[tex]Ka_1 = \frac{[H^+][H_2A^-]}{[H_3A]} = \frac{(x)(x)}{(0.100 - x)}[/tex]
[tex]\text{x to be much smaller than 0.100 M}\\\\to 6.31 \times 10^{-3} = \frac{x^2}{0.100}\\\\\to x^2 = 6.31 \times 10^{-4}\\\\ \to x = 0.025\ M\\\\\to pH = -\log_{10}[H^+] = -\log_{10}(0.025) = 1.60[/tex]
Barb has a bucket of snow with a mass of 20 kg. After the snowmelts,what will most likely be the mass of the bucket of water?
Answer:
20 kg
Explanation:
the mass wont change, so it will still be 20 kg
hope this helps :)
20kgs is the right answer/choice.