Answer:
d. The density of a substance is always the same, regardless of temperature.
Explanation:
Density is a characteristic property of water and defined as the mass per unit volume.
The density of a substance always remains the same at the same temperature regardless of the size of the sample. The density of the sample changes with temperature and pressure. for example : The density of a substance increases with a decrease in temperature as the volume increases.
Hence, the statement about density is not true is " d. The density of a substance is always the same, regardless of temperature."
A student submits the following work on the mass number, but he has made a few mistakes. Select the sentences that are incorrect.
Calculating the mass number for an atom requires that we know the atomic number and the number of protons in the atom’s nucleus. The mass number then gives us the average weight of atoms of a given element. Specifically, these units are calibrated by setting the mass number for carbon-12 as 12 atomic mass units. Neutrons and protons have the same masses. However, as long as the number of protons equals the number of neutrons, the values balance out and we always obtain a whole number for the mass number.
Answer
Calculating the mass number for an atom requires that we know the atomic number and the number of protons in the atom’s nucleus. The mass number then gives us the average weight of atoms of a given element. However, as long as the number of protons equals the number of neutrons, the values balance out and we always obtain a whole number for the mass number.
Explanation:
those 3
There are two types of physical changes and chemical reactions- endothermic and exothermic. On the diagram below, which picture (A or B) is endothermic and which picture (A or B) is exothermic? Be sure to explain your reasoning for both.
Answer:
it is b because its releases heat in to all directions and not b because it staying inside and not releasing anything :)
Explanation:
Answer:
In ice cube heat is taken in absorbed it's an endothermic reaction
In fire heat is given out it is an exothermic reaction
Explanation:
Wanna give you one advice
Exit of heat means exothermic and you can memorize it by
The first word of both word exit ;exo
Hope it helps you
Intensive or Extensive?
The shipping cost of a book(depends on weight)
The number of pages in the first chapter.
The number of pages in a book.
The characterization of the following statements with respect to intensive or extensive is as follows:
The shipping cost of a book(depends on weight): Extensive.The number of pages in the first chapter: Intensive.The number of pages in a book: Intensive. What is Extensive?Extensive may be defined as terminology that illustrates any event or action which is extremely large and significantly found at the outer level of any referring details. For example, the shipping cost of a book (depends on weight) is mentioned outside the cover of the book.
Intensive may also be characterized as a scientific terminology that significantly deals with any object or details which is present inside the content. For example, the number of pages in a book is mentioned inside the book.
Therefore, the characterization of the following statements with respect to intensive or extensive is appropriately described above.
To learn more about Extensive and intensive, refer to the link:
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Left: red and white rock with rounded grains and coarse texture. Right: flat, gray rock composed of thin layers.
Which statement about the rocks is accurate?
The rock on the right is foliated.
The rock on the left formed from granite.
The rock on the left is formed from cooled magma.
The rock on the right has randomly arranged grains.
Answer:
The rock on the right is foliated
Explanation:
I took the test
Which non-metal have lustre in the following 1. Iodine 2. Chlorine 3. Carbon 4. Silicon
Answer:
Iodine
Explanation:
I hope this answer will help you
Answer:
silicon. ?
Explanation:
lmk if its right.
Which two elements have similar characteristic
Answer:
Ca and Ba
Explanation:
Mainly because both Ca and Ba are able to form ionic bonds also both Ba and Ca are earth, in that case they have similar characteristics
How many grams are in 2.75 moles of Calcium
Answer:
110.21 g/mol
............................
Answer:
110.22 g in 2.75 moles of calcium
Explanation:
to convert moles to grams
moles (g/mol)
2.75 mol Ca (40.08 (atomic weight) g Ca/1 mol Ca)= 110.22
What volume will 250. mL of gas at STP occupy ig the pressure changes to 2.0 atmospheres and the temperature changes at 30 degrees Celsius
Answer:
it is 75 degrees
Explanation:
Volume is 138.7 mL.
The equation for calculation of volume is as follows:-
[tex]\frac{P_1V_1}{T_1} =\frac{P_2V_2}{T_2}[/tex]
STP:-
Temperature=273 K
Pressure=1 atm
[tex]\frac{1 atm\times250mL}{273 K} =\frac{2 atm\times V_2}{303\ K}\\V_2=138.7\ mL[/tex]
Hence, the volume is 138.7 mL.
To know more about:-
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Which force is equal but opposite to the one shown?
O A. Air resistance applying a normal force on the horse
O B. The ground applying a force on the horse
C. Gravity applying a downward force on the horse
D. The horse applying an action force on the ground
PREVIOUS
Answer:
b
Explanation:
Which of the situations below describes an ethical dilemma related to food
engineering?
A. Educational seminars should be conducted to help consumers
grow their own crops.
B. Production plants should be located close to consumers so
distribution runs efficiently.
C. Pesticides protect our crops, but some European countries have
linked them to thyroid disorders.
D. Preservatives must be used so that food can reach the consumer
before spoiling
Answer:
C. Pesticides protect our crops, but some European countries have
linked them to thyroid disorders.
Explanation:
Researches involving human or sometimes animals are subject to critical decision making.
They can easily trespass on the fundamental rights of people and some other issues.
The use of pesticides on a crop which can lead to thyroid disorder is an ethical dilemma. In this case, the pesticide helps to prevent crop loss due to the invasion of pests. This will boost food production and ensure food is availableLikewise, the application of the pesticide causes thyroid issues. This is an ethical dilemma issue.If the density of a substance is 2.18 g/mL, how would you find the density given that the mass is 0.987 kg and the volume is 4.52 x 102 mL?
Answer:
Explanation:
Convert mass in gms .. 987 gms
Density = mass/ volume
= 987/4.52 x102
= 2.18 g/mL
What is Chlorofluorocarbons?
Answer:
Chlorofluorocarbons and hydrochlorofluorocarbons are fully or partly halogenated paraffin hydrocarbons that contain only carbon, hydrogen, chlorine, and fluorine, produced as volatile derivative of methane, ethane, and propane. They are also commonly known by the DuPont brand name Freon.
Explanation:
Answer:
Explanation: Chlorofluorocarbons and hydrochlorofluorocarbons are fully or partly halogenated paraffin hydrocarbons that contain only carbon, hydrogen, chlorine, and fluorine, produced as volatile derivative of methane, ethane, and propane. They are also commonly known by the DuPont brand name Freon
hope that helps.↑What is the kinetic energy of a 100 kg bear running at 3 m/s
Answer:
The answer is 450 JExplanation:
The kinetic energy of a body can be found by using the formula
[tex]KE = \frac{1}{2} m {v}^{2} \\ [/tex]
where
m is the mass
v is the velocity
From the question
m = 100 kg
v = 3 m/s
We have
[tex]KE = \frac{1}{2} \times 100 \times {3}^{2} \\ = 50 \times 9[/tex]
We have the final answer as
450 JHope this helps you
A lump of chromium (Cr) has a specific heat of 0.448J/g℃. It is heated to a temperature of 89.5℃ and placed into a calorimeter with 75.2 mL of water at 20.5℃. After stirring, the final temperature of the water, Cr metal, and calorimeter is 27.4℃. What is the mass of Cr metal?
Answer:
Mass of Cr= 78 g
Explanation:
Given data:
Specific heat of Cr = 0.448 j/g.°C
Initial temperature of Cr lump = 89.5°C
Mass of water = 75.2 mL or 75.2 g
Initial temperature of water = 20.5°C
Final temperature of water = 27.4°C
Mass of Cr = ?
Solution:
when we placed the lump of Cr metal into water heat lost by limp is equal to the heat gain by water.
Specific heat capacity of water is 4.184 j/g.°C
Q = mcΔT
Q = 75.2 g× 4.184 j/g.°C × (27.4°C - 20.5°C)
Q = 2171 J
Heat lost by Cr lump is -2171 J. Now we will calculate the mass of Cr.
Q = mcΔT
-2171 J = m ×0.448 j/g.°C × ( 27.4°C- 89.5°C)
-2171 J = m × -27.821 j/g
m = -2171 J/-27.821 j/g
m = 78 g
The liquid inside a cell is called?
Answer:
cytoplasm
Explanation:
cytoplasm carries the nutrients of the cell
Please Helpp
Which organelle is correctly matched with the cell process it performs?
A Vacuole — photosynthesis in plant leaf tissue
B Chloroplast — water storage in plant leaf tissue
C Mitochondria — energy production in plant and animal tissue
D Cell wall — supporting the cell in animal tissue
Answer:
Mitochondria - energy production in plant and animal tissue
Explanation:
The mitochondria is the power house of a cell. it contains adenosine-tri- phosphate or ATP molecules that produce energy through active transport. The mitochondria is responsible for energy production in both plant and animal cells
Which of the following statements concerning the measured number 0.3030
is correct? *
a) Only one of the zeros in the number is significant
b) Rounded off to 2 significant figures the number becomes 0.30.
c) Expressed in scientific notation the number becomes 3.03 x 10-1.
O
d) more than one correct response
e) no correct response
der below
Please explain why your answer is correct and why the others are incorrect :)
Answer:
C
Explanation:
If you move the decimal to the left it transforms the expression into scientific notation.
whats the mass number for titanium if it has 27 neutrons?
Answer: 49
Explanation: Mass number is protons + neutrons. So that would be 22 + 27 which gives you 49
: Question List
Question 9 of 15
Total Points: 1 out of 15
The configuration notation shown is for the the element
?
1s^2 2s^2 2p^6 3s² 3p 4s^1
calcium
magnesium
potassium
sodium
A neutral atom of sulfur becomes an ion with a negative two charge by?
Answer:
The valence shell (the 3s and 3p sublevels) contains six electrons, but it needs eight to become stable. Think of the octet rule. Therefore a sulfur atom will gain two electrons to form the sulfide anion with a charge of 2− , with the symbol S2− .
what is biogas, biomass and biodigester
Answer:
Biogas is a type of biofuel that is naturally produced from the decomposition of organic waste. When organic matter, such as food scraps and animal waste, break down in an anaerobic environment (an environment absent of oxygen) they release a blend of gases, primarily methane and carbon dioxide.
Explanation:
Biomass is renewable organic material that comes from plants and animals. ... Biomass contains stored chemical energy from the sun. Plants produce biomass through photosynthesis. Biomass can be burned directly for heat or converted to renewable liquid and gaseous fuels through various processes.biodigester is like a mechanical stomach. It is fed with organic material, which is broken down (decomposed) by micro-organisms (bacteria) is an oxygen-free (anaerobic) environment to produce a renewable energy called biogas (methane and carbon dioxide) and other material that is mainly used as fertilizer.
Explanation:
Biogas is a type of biofuel that is naturally produced from the decomposition of organic waste.
Biomass is plant or animal material used for energy production, or in various industrial processes as raw substance for a range of products.
A Biodigester simply means a tank which digests organic material biologically. In this sense, the FilterPod is a biodigester. However, many people think of a biodigester as a tank which digests, anaerobically, without air, organic material and produces methane gas for cooking, lighting and heating ect.
What would happen to the rate of a reaction if the concentration of substrate was increased after the point of saturation?
a)The reaction rate would increase.
b)The reaction rate would decrease.
c)There would be no effect.
Answer:
there would be no effect
Explanation:
Which phrase describes density?
O height of a point above sea level
O force pushing on an area or a surface
O amount of mass in a certain volume
O amount of matter an object contains
Answer:
C: amount of mass in a certain volume
Explanation:
Just took the quiz and got 100%
How does density affect the water cycle
Explanation:
Biological in the ocean is affected by the water cycle via the Mixed Layer Depth and Run off from land. Salinity and temperature determine the density of ocean water, and density influences the circulation. E-P determines surface salinity of the ocean, which helps determine the stability of the water column.
which observation provided Albert Einstein the clue that he needed to explain the photoelectric effect?
Answer:
Which observation provided Albert Einstein the clue that he needed to explain the photoelectric effect? Energy of electrons depends on light's frequency, not intensity. A change in which property of light will have no effect on whether or not the photoelectric effect occurs?
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
SiS is what type of mineral?
POSSIE Gallium (Ga) is a soft, silvery metal used primarily in electronic circuits, semiconductors, and light-emitting diodes (LEDs). It is also useful in high-temperature thermometers, barometers, pharmaceuticals, and nuclear medicine tests. Which electron configuration represents the electrons in an atom of gallium at ground state? O1s 2s22p63s23p64524d104p? O 182 2s22p63s23p64s24p1 o 1s 2s22p63s23p64823d104p? O 182 2s22p63s23p64s3
The ground state configuration : 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4p¹
Further explanationElectrons can move the shell up or down by releasing energy or absorbing energy
It can be concluded that there are 2 conditions:
Ground-state is the state of electrons filling the shell with the lowest energy levels.
Excited-state is the state of electrons which occupies a higher energy level
The state of excited electrons can be seen from the presence of electrons which do not fill the shell completely but fill the shell afterward
Gallium (Ga) is a metal located in group 13, p-block and period 4
Atomic number : 31
If we look at the options:
options 1,2 and 3 do not conform to Aufbau principle(Electrons occupy orbitals of the lowest energy level ), because 3d orbitals do not exist and the number of electrons is also not 31
So that the most appropriate electron configuration is:
1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4p¹ = 31 electrons
or we can write : [Ar] 4s² 3d¹⁰ 4p¹
Using the balanced equation below,
how many grams of cesium xenon
heptafluoride would be produced
from the complete reaction of 37.8 g
cesium fluoride?
CsF + XeF6 => CsXeF7
Answer:
Mass of CsXeF₇ = 99.3 g
Explanation:
Given data:
Mass of CsF = 37.8 g
Mass of CsXeF₇ produced = ?
Solution:
Balance chemical equation:
CsF + XeF₆ → CsXeF₇
Number of moles of CsF:
Number of moles = mass/molar mass
Number of moles = 37.8 g/ 152 g/mol
Number of moles = 0.25 mol
Now we will compare the moles of CsF with CsXeF₇ from balance chemical equation:
CsF : CsXeF₇
1 : 1
0.25 : 0.25
Mass of CsXeF₇ :
Mass = number of moles × molar mass
Number of moles = 0.25 mol × 397.2 g/mol
Mass = 99.3 g
Answer:
98.84
Explanation:
An 8th grade goes to a restaurant for dinner with their family. At dinner, the student orders iced tea. The ice and tea combined to weigh 210 grams. The student then added sugar and lemon to their tea. The sugar weighed 20 grams and the lemon weighed 15 grams. After adding the sugar and lemon, the student stated the tea weighs 225 (210 grams ice & tea + 15 grams lemon) grams since only the lemon would add weight to the tea because the sugar was dissolved. Do you agree or disagree with the statement? Justify your choice.
Answer:
Disagree, the total mass is 245 grams.
Explanation:
We need to keep in mind the Law of Conservation of Mass. Each gram added to the lemonade (a system) will remain there unless it is somehow removed. The added mass of both sugar and lemon count for the total mass (210+20+15), even if the sugar was dissolved.