Answer:
The percent error is 0.023%.
Explanation:
Pre-weighed of a quarter is 5.6026 g.
The weight that the student obtains for the same quarter is 5.6013 g.
We need to find the percent error in the students reading. It is given by the formula as follows :
[tex]\%=\dfrac{|\text{original value-calculated value}|}{\text{original value}}\times 100[/tex]
Putting all the values, we get :
[tex]\%=\dfrac{5.6026 -5.6013 }{5.6026 }\times 100\\\\\%=0.023\%[/tex]
So, the percent error is 0.023%.
Which of the following elements would be brittle?
Sulfur
Magnesium
Rubidium
Lithium
Answer:
Sulfur
Explanation:
Which of the following is true about pure substances? A. A pure substance has the same chemical properties throughout. All pure substances are unable to be separated by any means. c. A pure substance can only be made up of one kind of atom. D. A pure substance can always be separated by physical means.
Answer:first one
Explanation:
A pure substance has same chemical properties throughout , it cannot be separated by any means and it is made up of one kind of atom.
What are chemical properties?
These properties are defined as those properties which become evident during or after a chemical reaction after the identity of the substance is changed during chemical reaction.
These properties cannot be determined externally just by viewing the substance ,these change immensely after a substance undergoes a chemical change.These are used for identification of unknown substances and for building up chemical classifications.
The major chemical properties are flammability,toxicity,reactivity,acidity and heat of combustion.For a chemical property to be apparent , it is necessary that the structure of the substance is altered.
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Which materials sink in water? Hint: There is more than one nightanswer. Rubber Wooden Ball Ice Granite Titanium
Answer:
Granite and Titanium will sink
Explanation:
Granite and Titanium will sink in water.Granite and Titanium will sink in water because density of Granite and Titanium is higher then water. Also there raw shape does not help them to float on water.
Elements in group to are cold alkaline earth metals what is most similar about alkaline earth metals how many protons and neutrons they have which Chemical properties he have how many total electrons they have which period They have most often found in
Answer:
explanations below
Explanation:
The alkaline earth metals are the 6 chemical elements that can be found in group two of the periodic table. These elements have a lot of properties in common, in the sense that they are generally shiny, reactive at standard temperature and pressure and they are also silvery-white. The elements are beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra)
These metals have two electrons at their orbits, which can be easily lost to form cations (with charge +2, and an oxidation state of +2)
Below are some of their details
Name: Beryllium
Number of Protons/Electrons: 4
Number of Neutrons: 5
Name: Magnesium
Number of Protons/Electrons: 12
Number of Neutrons: 12
Name: Calcium
Number of Protons/Electrons: 20
Number of Neutrons: 20
Name: Strontium
Number of Protons/Electrons: 38
Number of Neutrons: 50
Name: Barium
Number of Protons/Electrons: 56
Number of Neutrons: 81
Name: Radium
Number of Protons/Electrons: 88
Number of Neutrons: 138
Calculate the density of helium if a balloon with a capacity of 5.00 L holds 0.890 g.
Answer:
Explanation:
Density is m/V. Also, 1 liter = 1000 [tex]cm^3[/tex]. So, we get 0.890/(5*1000) = [tex]1.78*10^{-4}[/tex] g/cm^3. You can convert this to kg/m^3 as well by multiplying it by 10. Depends which one you want.
The ratio of the mass in grams and volume in cubic meters gives the density. The density of 0.80 gm helium is 1.78 × 10 ⁻⁴ g/cm³.
What is density?Density is the amount or the number of entities that can be contained in an area. It is denoted by ρ and is calculated as,
Given,
Mass = 0.890 gm
Volume = 5000 cm³
ρ = Mass ÷ Volume
= 0.890 ÷ 5000
= 1.78 × 10 ⁻⁴ g/cm³
Therefore, 1.78 × 10 ⁻⁴ g/cm³ is the density of helium.
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Scott and James work at a grocery store. After the grocery
store closed, they were playing a game with a shopping cart
and Scott's skateboard. They crashed the skateboard and
the shopping cart two times. The shopping cart had more non
Answer: b) Crash 2; the force on the cart was stronger in this crash, so the force on the skateboard was also stronger.
Explanation:
helppppppppppppp plzzzzzzzz Identify each structure based on its label.
Compound A is a
amine.
Compound B is a
amine.
Compound C is a
amine.
Compound D is
.
Answer:
kldja
Explanation:
A.) primary
B.) tertiary
C.) secondary
D.) ammonia
edge2020
A cube of metal has a mass of 5.05 x 10°g and its density is known to be 12.77 g/mL, what is the volume of this metal?
A 395.5 mL
B. 2.529 mL
C. 63,910 mL
D. 64.48 ml
Answer:
Explanation:
option A is correct
How many hydrogen atoms are in 2h2+02—2h20?
Answer: Two hydrogen atoms
Explanation:
A water molecule (formally known as dihydrogen monoxide) is composed of two hydrogen atoms and one oxygen atom. But you can't simply take two hydrogen atoms and stick them onto an oxygen atom. The actual reaction to make water is a bit more complicated: 2H2 + O2 = 2H2O + Energy.
What is ionization energy?
Your science teacher removed the gas from a birthday balloon. They discovered that the gas is made of the element helium. Inside that atom is:
A. A new substance
B. Protons, neutrons and electrons
C. A different element
D. All of the above
How does a heat affect the chemical reaction?
Answer:
Increasing the temperature increases reaction rates because of the disproportionately large increase in the number of high energy collisions. It is only these collisions (possessing at least the activation energy for the reaction) which result in a reaction.
Explanation:
The speed of light in plastic is 2.0 x 108 m/s. Calculate the index of refraction for
plastic.
Answer:
n=c/v.
1.5=3×10^8/v
v=3×10^8/1.5
v=2×10^8 m/s
Hope this helps :)
The index of refraction for plastic, when speed of light in plastic is 1.5.
How do we calculate refraction index?Refraction index of any substance will be calculated by using the below equation:
n = c/v, where
c = speed of light in vaccum = 3×10⁸ m/s
v = speed of light in plastic = 2×10⁸ m/sec
On putting values in the above equation, we get
n = 3×10⁸ / 2×10⁸ = 1.5
Hence the refractive index of plastic is 1.5.
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A student lives in an apartment complex next to a park and train tracks. The student observes that they can hear the train coming sooner and from farther away when they are in front of their apartment and can only barely hear the train when they are in the park despite both being the same distance from the railroad tracks.
The student developed the model above. Using the model, identify two potential wave phenomena that occur and are the reason behind why the student can only hear the train in front of the apartment complex.
A.
The train can be heard more easily in front of the apartment complex because of reflection and interference. As the sound comes from the train, the sound waves reflect off of the complex and interfere with each other increasing the amplitude of the wave to make it easier to hear.
B.
The train can not be heard as easily in the park because of reflection and diffraction. The sound reflects off of the trees in the park and diffract between the trees, this causes the waves to bend too much to be heard.
C.
The train can be heard more easily in front of the apartment complex because of diffraction and refraction. The sound waves diffract between the other buildings aiming them towards the apartment complex and then the sound refracts through the apartment complex which makes it more difficult to hear in the park.
D.
The train can not be heard as easily in the park because of interference and reflection. The other buildings in front of the park cause interference of the sound waves from the train and the trees in the park cause reflection making it too hard to hear the train.
Answer:
The answer is A
Explanation:
A piece of metal with a volume of 2.45 mL has a density of 4.255g/mL. What is the mass of the metal?
Answer:
The answer is 10.42 gExplanation:
The mass of a substance when given the density and volume can be found by using the formula
mass = Density × volumeFrom the question
volume = 2.45 mL
density = 4.255g/mL
We have
mass = 2.45 × 4.255 = 10.42475
We have the final answer as
10.42 gHope this helps you
will give brainlliest
Which noble gas is closest to sulfur, S, on the periodic table? What has to happen for a sulfur atom in order to have an electron arrangement similar to the nearest noble gas?
Answer: argon
What must happen to a sulfur atom in order for it to have an electron arrangement similar to that of a noble gas? Answer: The noble gas closest to sulfur is argon. A sulfur atom gains two electrons to have an electron arrangement similar to that of argon.
Explanation:
Help ASAP plzzzz!!!!!!!!
Answer:
Granite Solid
Milk Liquid
Neon is gas
Wood Is solid
Paper is solid
Helium is Gas
Water is liquid
Air is Gas
Alcohol is liquid
Metal is solid
Nitrogen is gas
Juice is liquid
Oil is liquid
Water Vapor is Gas
Brick is Solid
Propane is Gas
Fabric is solid
Gasoline is Liquid
Explanation:
Hope Dis helped :D :3
If a p-wave arrives at 2:10:00 and the s-wave arrives at 2:15:20, how many kilometers from the epicenter is a location?
Answer:
2.67 x 10⁷km
Explanation:
Given parameters:
Time of arrival of p-waves = 2: 10: 00
Time of arrival of s-waves = 2: 15: 20
Unknown:
Distance of wave from epicenter = ?
Solution:
To find the distance of the wave from the epicenter;
Distance = 3 x 10⁸ x time interval
Time interval = Time of arrival of p-waves - Time of arrival of s-waves
= 2: 10: 00 - 2: 15: 20
= 5min 20s
= 320s
Now, we need to convert the time to hrs;
3600s = 1hr
320s = [tex]\frac{320}{3600}[/tex] = [tex]\frac{4}{45}[/tex]hr
So,
Distance = 3 x 10⁸ x [tex]\frac{4}{45}[/tex] = 2.67 x 10⁷km
A
Carpet is beaten to
beaten to remove dust
Answer:
It's Clean?
Explanation:
Does the use of lithium cause human health problems?
Answer:
Yes
Explanation:
Lithium can cause nausea, diarrhea, dizziness, change in heart rhythm, muscle weakness, fatigue, and a dazed feeling
Continued use of Lithium could mean fine tremor, frequent urination, and thirst
Source: Webmd.com
Where do rivers usually begin?
at the ocean
at groundwater outlets
in mountainous regions
in lakes and larger rivers
Answer:
in mountainous regions
Explanation:
The rivers usually begins in mountainous regions. A river's source is typically located in a high area, such a mountain or a hill. A river may have several sources. Some rivers start where an underground natural spring discharges water.
What is a mountain ?A mountain is an elevated area of the crust of the Earth, typically with steep sides that reveal a substantial amount of bedrock that has been exposed.
Although definitions vary, a mountain is often taller than a hill, rising normally at least 300 meters above the surrounding terrain, and differs from a plateau in having a constrained peak region.
Every river has a beginning place where the water flow starts. We refer to this source as a headwater. Some rivers have their beginnings in hills or mountains, where rainwater or snowmelt gathers and creates little channels.
It is possible for the headwater to originate from mountain snowmelt or rainfall, but it is also possible for it to bubble up from the ground or develop at the edge of a lake or big pond.
Thus, option C is correct.
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if atom X has 6 protons,6 neutrons and 6 electrons and aton Z has 6 protons,7neutrons and 6 electrons,atom x and atom z are isotopes of the element
If a wave of red light has a wavelength of 6.7 x 10-7 m, will the frequency of the red wave be high or low?
Answer:
Its high
Explanation:
Becuase if u times it what do u get
Please help brainiest is award!
Answer: A.
Explanation:
The molecular formula for glucose is C6H12O6. This means that there are 6 carbon atoms, 12 hydrogen atoms, and 6 oxygen atoms bonded together to make one molecule of glucose.
Hopes this helps!
Describe how calcium and fluorine bond together to form calcium fluoride. The electron arrangement of each atom is shown.
Answer:
Detail is given below.
Explanation:
Calcium is alkaline earth metal. It has two valance electron. Thus calcium needs six more electron to complete the octet. Thus, its very easy for calcium to remove its two electron and get complete octet.
Electronic configuration of Ca:
Ca₂₀ = [Ar] 4s²
While,
Fluorine is halogen. It has seven valance electrons. It needed only one electron to complete the octet. When it combine with calcium , calcium loses two electrons thus two atom of fluorine combine with one atom of fluorine and stable compound calcium fluoride is formed.
Electronic configuration of F:
F₉ = [He] 2s² 2p⁵
Chemical equation:
Ca + F₂ → CaF₂
Write the chemical symbols for three different atoms or atomic cations with 26 electrons.
The chemical symbols for three different atoms or atomic cations with 26 electrons are Fe, [tex]Co^+[/tex], [tex]Ni^{2+}[/tex]
Explanation:
The atomic number of an atom is equal to the number of protonsAn atom is neutral, it has an equal number of electrons and protons.Element with atomic number 26 is Iron, Fe.A neutral atom of iron has an equal number of protons and electrons.Cobalt has an atomic number of 27.A neutral atom of cobalt has an equal number of protons and electrons.Cobalt has 27 electrons and by losing one electron it will form a cobalt (I) ion with 26 electrons.The cobalt (I) ion has 26 electrons, [tex]Co^+[/tex].Nickel has an atomic number of 28.A neutral atom of nickel has an equal number of protons and electrons.Nickel has 28 electrons and by losing two electrons it will form a nickel(II) ion with 26 electrons.The nickel (II) ion has 26 electrons,[tex]Ni^{2+}[/tex].So, from this, we can write chemical symbols for three different atoms or atomic cations with 26 electrons are Fe, [tex]Co^+[/tex], [tex]Ni^{2+}[/tex].
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Count the total number of atoms in CH4:
Answer:
5 atoms
Explanation:
there is 1 carbon atom and 4 hydrogen atoms
How many atoms are in this formula? 2Fe
Answer:
two
Explanation:
There are two atoms in 2 Fe, more correctly written as 2Fe or Fe2. Both atoms are from the same element, iron.
Answer:
2
Explanation:
There are two atoms of the same element in 2Fe.
Hope this helps! :)
3.58 x 1023 molecules of propane C8H8 would occupy how much space at STP
Answer: At STP, a mole of gas takes up 22.4 Liters. The 22.4 Liters/mole quantity can be derived from the Ideal Gas Law, PV = nRT, plugging in STP conditions for P and T, and solving for V/n, which gets 22.4 Liters/mole.
Explanation:
Un estudiante preparo 200 ml de solución de acetato de potasio (CH3COOH ; Masa molar = 98 g/mol ; Ka CH3COOH = 1,8 x 10-5), disolviendo 3,5 g de ácido, la que denomino "Solución A". Posteriormente preparo otra solución de menor concentración del mismo soluto que denomino "solución B" y para ello tomo un volumen de 5,5 ml de la solución A y agrego agua hasta 70 ml de solución. Señale el pH de solución A y B y, la concentración molar de CH3COO- en la solución b.
Answer:
mirar respuesta abajo
Explanation:
Muy bien. Antes de responder lo que piden en el problema, vamos a calcular la concentración inicial de la solución A:
1) Concentración de la solución A:
En este caso, se sabe que se usaron 3,5 g de la sal, se puede calcular los moles usando el peso molecular y la masa:
n = m/PM (1)
Aplicando tenemos:
n = 3,5 / 98 = 0,0357 moles
Conociendo los moles, podemos calcular la concentración:
M = n/V (2)
Aplicando la formula tenemos:
M = 0.0357 / 0.200 = 0.1785 M
Esta es la concentración del ácido etiquetado como "Solución A".
Ahora podemos ver la concentración de la solución B, para luego calcular las concentraciones molares de los iones en solución y sus respectivos pH.
2) Concentración del ácido en la solución B:
Con la concentración de "A", se puede determinar la concentración de la solución B. Aqui podemos esperar que sea un valor mas bajo, puesto que es una dilución la que estamos haciendo. Por lo tanto.
Si se toma 5.5 mL de la solución A, entonces:
n = 0.1785 * 0.0055 = 0.00098 moles
Con esto, se calcula la nueva concentración:
M = 0.00098 / 0.070 = 0.014 M
Esta es la concentración de la solución B. Ahora para calcular pH y concentraciones de los iones en equilibrio, hay que plantear la reacción acido base en equilibrio. Como es el mismo compuesto, usaremos la misma ecuación.
3) pH de las soluciones A y B:
Planteamos la reacción de equilibrio:
CH₃COO⁻ + H₂O <------> CH₃COOH + OH⁻ Kb
Calculando el Kb, sería asi:
Kb = Kw/Ka
Kb = 1x10⁻¹⁴ / 1.8x10⁻⁵ = 5.56x10⁻¹⁰
Ahora reescribimos la ecuación y hacemos una tabla de equilibrio:
CH₃COO⁻ + H₂O <------> CH₃COOH + OH⁻ Kb = 5.56x10⁻¹⁰
i) 0.1785 x x
eq) 0.1785-x x x
Kb = [OH⁻] [CH₃COOH] / [CH₃COO⁻]
Reemplazando nos queda:
5.56 * 10⁻¹⁰ = x² / (0.1785-x)
Y como Kb es muy pequeño, se asume que el valor de x será también pequeño, asi que podemos redondear la resta a simplemente 0.1785, quedando tan solo:
5.56 * 10⁻¹⁰ = x² / (0.1785)
x² = 5.56*10⁻¹⁰ * 0.1785
x = √9.9246*10⁻¹¹
x = 9.96*10⁻⁶ M
Esta es la concentración de [OH⁻] y [CH₃COO⁻] en la solución A.
Aplicando lo mismo para la solución B (Cambiando solo el dato de concentración) nos queda:
x = √5.56*10⁻¹⁰ * 0.014
x = 2.79x10⁻⁶ M = [OH⁻] = [CH₃COO⁻]Finalmente, para calcular pH, se calcula primero el pOH y luego el pH:
pH = 14 - pOH
pOH = -log[OH⁻]
Para la solución A:
pOH = -log(9.96*10⁻⁶) = 5
pH = 14 - 5
pH = 9En el caso de la solución B:
pOH = -log(2.79*10⁻⁶) = 5.55
pH = 14 - 5.55
pH = 8.45Espero te ayude