Answer:
45.0
Explanation:
Using the rules of rounding, we can round 44.981 to 45. We need that third sig fig though, so we add the trailing zero
The value 44.981 g to three significant figures is 45.0 g.
Significant figures, also known as significant digits, are the digits in a number that carries meaning in terms of precision and accuracy. They indicate the certainty or reliability of a measurement or calculated value.
To round the value 44.981 g to three significant figures, follow the rules for significant figures:
Identify the three most significant digits in the number. They are 4, 4, and 9.
Look at the digit immediately after the third significant digit. If it is 5 or greater, round up; if it is less than 5, round down.
In 44.981 g, the digit immediately after the third significant digit (9) is 8. Since 8 is greater than 5, round up.
Therefore, rounding 44.981 g to three significant figures gives us:
45.0 g.
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Juan fills two separate beakers with boiling water. The first beaker holds 500 mL. The second beaker only holds 75 mL. Juan then measures the temperature of both beakers and calculates how long it takes the water in each beaker to reach room temperature. Which of the following is true?
Answer:
The water in the 75 mL beaker will cool down more rapidly then the water in the 500 mL beaker.
Explanation:
The scale of an object influences the object's properties. For example, the water in a small beaker loses heat more rapidly than the water in a large beaker. This is because heat loss decreases as volume increases. As the scale of a beaker increases, its volume increases. Therefore, the larger the beaker, the slower the water inside the beaker will cool.
When a solid is placed in a container and heat is applied, a phase change occurs. Watch the video and identify which of the following statements are correct.
a) The temperature increases while all of a liquid is converted to a gas.
b) The average kinetic energy of the system changes while all of a solid is converted to a liquid.
c) Temperature remains constant while all of a solid is converted to a liquid.
d) When heat is applied to a solid, the molecular motion decreases as the temperature increases.
e) When a solid is converted to a liquid, heat is absorbed.
Answer:
Temperature remains constant while all of a solid is converted to a liquid.
When a solid is converted to a liquid, heat is absorbed.
Explanation:
During a phase change, the temperature of the system remains constant. Recall that latent heat is defined as heat that causes a change of state without a corresponding rise in temperature of the system.
When a solid is converted to a liquid, latent heat of fusion is involved hence the temperature of the system remains constant throughout the process.
Similarly, heat is absorbed as intermolecular forces are broken up and the would converts to liquid.
Which of the following correctly
states the difference between
elements and compounds?
Elements and compounds are the
same because they are both made of
atoms,
An element is made of two or more
types of atoms combined, while a
compound is made of one type of
stom,
An element is made of one type of
tcom, while a compound is two or
more types of stoms combined.
Answer:
An element is made of one type of atom, while a compound is two or
more types of atoms combined.
Explanation:
An element is a distinct substance that cannot be split up into simpler substances. Elements are substances that consists of only one kind of atom.
Compounds are substances composed of two or more kinds of atoms/elements joined together in a definite grouping.
There are over a hundred elements known to date. Each one of the elements is symbolized by a capital or a capital letter followed by a small letter derived from English, Latin or Greek Examples are copper, gold, ironThe properties of a compound are distinct and different from those of the individual elements that are combined in its make up. There are several millions of compounds known. They are usually represented by chemical formulae.As we can see, compounds are indeed made up of more than one types of atoms whereas an element is made up of just one single atom.
Selenium-81 has an abundance of 21.91% and a mass of 80.65 amu.
Selenium-84 has an abundance of 23.35% and a mass of 83.67 amu.
Selenium-80 has an abundance of 54.74% and a mass of 79.64 amu.
What is the average atomic mass of Selenium according to these values?
Answer:
80.80amu
Explanation:
multiple each value by its percentage (in decimal form) and take the sum.
80.65x.2191 + 83.67x.2335 + 79.64x.5474 = 80.802296 sig figs = 80.80
Which of the following describes geothermal energy in use?
A
A drought in recent years has lowered the amount of hydroelectric power produced by the Hoover Dam.
B
The wide open land and strong gusts of the Greater Accra region in Ghana make it a perfect location for multiple turbines.
C
Iceland is situated on top of multiple volcanoes and harnesses this natural power to heat the roads and sidewalks in the winter.
D
Innovators are working to create panels to replace asphalt on highways, so roadways can generate energy from the sun even as cars burn fossil fuels.
The statement which describes geothermal energy in use is iceland is situated on top of multiple volcanoes and harnesses this natural power to heat the roads and sidewalks in the winter.
What is geothermal energy?Geothermal energy is the natural energy or we can say that renewable energy which can be used without any use of chemicals and damage of environment.
Geothermal energy is used for many purposes like hydroelectric energy, wind energy, solar energy, etc.
First and second options are not correct because in that utilization of geothermal is not mention.Iceland on the top of valconoes is used to warm up the roads and sidewalks in the winter season, this gives the importance of the geothermal energy.At the last option they are planning for the future utilization, so we will not consider that point for right now.Hence, iceland on top of volcanoes describe the use of geothermal energy.
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Plzzz help me answer this question!!,!
A hot pot with a closed lid is placed on a table. Something is placed in between the pot and the table to protect the table from heat. Why does the table need protection from heat?
26. A hot pot with a closed lid is placed on a table. Something is placed in between the pot and the table to protect the table from heat.
Question options:
The pot is an isolated system, heat and energy cannot escape
The pot is an open system, heat and matter can enter and leave the pot
The pot is an open system, heat can escape but matter cannot
The pot is a closed system, heat can escape but matter cannot
Answer:
The pot is a closed system heat can escape, but matter cannot
Explanation:
Plz help don’t understand.
Answer:
the last one i think
Explanation:
can someone please help me
HELP I'LL AWARD BRAINLIEST
Answer:
slope of line a: y=2x-2
slope of line b: y=2x+2
slope of line c: y=1x+2
Explanation:
hope this helps!!
When a sodium chloride (NaCl) solution is given to some intravenously (as an IV directly into the blood), it is usually a 0.9% NaCl solution. The reason is that a 0.9% NaCl is isotonic to your red blood cells. Use that information to answer the following questions: In the solution above, which molecule is acting as the solute and which molecule is acting as the solvent? If you replaced the 0.9% NaCl solution with pure water instead, would the water be hypertonic, hypotonic, or isotonic to your red blood cells? If you replaced the 0.9% NaCl solution with pure water instead, would the net (overall) movement of water be into the cell, out of the cell, or would there be no net movement of water? If you replaced the 0.9% NaCl solution with pure water instead and waited, what specifically would happen to your red blood cells?
Answer:
Explanation:
(1) In the IV solution, the solute here is the NaCl salt and the solvent is the liquid (water) the salt is dissolved in.
(2) If the NaCl is replace with water, the water content will become hypotonic to the red blood cells as there would be less solute in the solution than in the cell's cytosol. This also means there is more water in the solution than in the cell's cytosol.
(3) Because the water is hypotonic to the red blood cells (as described in (2) above), the net movement of water will be into the cell.
(4) If the movement of water is allowed to continue as described in (3) above (i.e if 0.9% NaCl in the solution is replaced with pure water instead and waited), the cell will rupture which can lead to cell lysis or cytolysis.
NOTE: An isotonic solution describes when there is the same amount of solute in the cell and the solution outside the cell hence there is little or no movement of water.
2. In India mostly ......
... are reared for getting wool.
Answer:
yes.... reared for getting wool.
How many atoms of H are in 11 moles of H2O
Answer:
1.325×10²⁵
Explanation:
1 mole of H2O has 2 mole of H atom
11 mole of H20 has 22 mole of H atom
we know
1 mole=6.023×10²³ atom
hence 22mole H =22×6.023×10²³
=1.325×10²⁵
5. The sphere shown below is placed in a full overflow cup and sinks to the bottom. How much water is displaced by the sphere?
4.6 cm
O A. 51.0 ml
OB. 66.5 ml
O C. 88.6 mL
O D.407.7 ml
Answer : The correct option is (A) 51.0 mL
Explanation :
As we know that water displaced is equal to the volume of sphere.
Now we have to determine the volume of sphere.
Formula used:
Volume of sphere = [tex]\frac{4}{3}\pi r^3[/tex]
where,
r = radius of sphere
Given:
Diameter of sphere = 4.6 cm
Radius of sphere = [tex]\frac{Diameter}{2}=\frac{4.6cm}{2}=2.3cm[/tex]
So,
Volume of sphere = [tex]\frac{4}{3}\times 3.14\times (2.3cm)^3[/tex]
Volume of sphere = [tex]50.94cm^3\approx 51.0 cm^3[/tex]
Water displaced = Volume of sphere = [tex]51.0 cm^3[/tex]
We know that:
[tex]1cm^3=1mL[/tex]
So,
Water displaced = 51.0 mL
Therefore, the correct option is (A) 51.0 mL
Answer:
A. 51.0 mL
Explanation:
i did this question in my quiz :)
What is the purpose of a catalyst?
O A. To change the potential energy of the reactants
O B. To lower the activation energy of a reaction
O C. To increase the kinetic energy of the reactants
O D. To shift the equilibrium position of a reaction
Answer:
To lower the activation energy of a reaction
Explanation:
i just took the test and got it right ...... i hope this helps :)
How can the knowledge of a material’s chemical makeup or use be utilized?
A. To classify minerals
B. To identify minerals
C. To determine the color of the minerals
D. To determine how to break down minerals
To identify minerals
Each material chemical makeup are a variety of chemical compounds which has each own category. They have different functional groups which helps people identify which material they look for. For instance, hydroxyl group has chemical makeup of alcohol
To identify minerals
Explanation:
Each material chemical makeup are a variety of chemical compounds which has each own category. They have different functional groups which helps people identify which material they look for. For instance, hydroxyl group has chemical makeup of alcohol
Electronegativity and ionization energy __________ from left to right within a period and __________ from top to
bottom within a group.
Answer:
C, increases/decreases
Explanation:
As you move down a group on the periodic table, the electronegativity of an element decreases because the increased number of energy levels puts the outer electrons very far away from the pull of the nucleus.
her Children to
She
School
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o took
Which one of the following reactions would produce the largest amount of heat
per mole of hydrogen?
A) C(s) + 2 H2 (g) CH4 (g) AH° = -74.9
kJ/mol
B) N2O (g) + 3 H2 (g) N2H4 (g)+ H2O (l)
AH° = -316.8 kJ/mol
C) 2 H2(g) + O2 (g) 2 H2O (l) AH° = -571.6
kJ/mol
D) N2 (g) + 3 H2 (g) 2 NH3 (g) AH° = -91.8
kJ/mol
Answer:
C) 2 H2(g) + O2 (g) 2 H2O (l) AH° = -571.6
kJ/mol
Explanation:
The magnitude of heat released in an exothermic reaction is shown by the magnitude of the change in enthalpy.
The more negative the enthalpy change of the reaction, the more the heat released by the process.
Hence, 2 H2(g) + O2 (g) 2 H2O (l) AH° = -571.6 kJ/mol has the most negative value of enthalpy change hence the greatest amount of heat is released in this reaction.
The reaction which would produce the largest amount of heat per mole of hydrogen is; Choice C: 2H2(g) + O2 (g). ===> 2 H2O (l) AH° = -571.6
AH° = -571.6kJ/mol.
According to the question;
We are required to identify the reaction which would produce the largest amount of heat per mole of hydrogen.It is evident that all the reactions are exothermic; the reactions release heat.
In essence, the reaction which produces the largest amount of heat is that with the largest negative enthalpy change, AH.In this scenario; the reaction that would produce the largest amount of heat per mole of hydrogen is Choice C: 2H2(g) + O2 (g) =====> 2 H2O (l) AH° = -571.6 kJ/mol
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How is this correct.how is this not wrong.Did you get it right.If you did explained please.
A compound is found to contain 40.05 % sulfur and 59.95 % oxygen by mass.
The empirical formula for this compound is
Answer:
im not good at chem
Explanation:
sorry bro
The empirical formula for the compound containing 40.05 % sulfur and 59.95 % oxygen is SO₃
Data obtained from the question Sulphur (S) = 40.05%Oxygen (O) = 59.95%Empirical formula =? How to determine the empirical formulaThe empirical formula of the compound can be obtained as follow
Divide by their molar mass
S = 40.05 / 32 = 1.25
O = 59.95 / 16 = 3.75
Divide by the smallest
S = 1.25 / 1.25 = 1
O = 3.75 / 1.25 = 3
Thus, the empirical formula of the compound is SO₃
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An atom has 6 protons, 7 neutrons and 5 electrons. what element is it?
Answer:
Carbon
Explanation:
Because it was very
a
Select the correct answer.
In which of these examples does chemical energy change to electrical energy?
A. digesting food
B. photosynthesis
O C. respiration
D. using a battery
Reset
Next
Answer:
D. Using a battery
Answer:
I hope this helps
Explanation:
Question 7 of 10
You have two pieces of metal. Metal A has a higher temperature than metal
B. What does this tell you about them?
A. The molecules in metal A are vibrating faster.
B. There is more light energy in metal B.
C. Metal B has more heat energy.
D. Metal A has more gravitational potential energy.
SUBMIT
Answer:
Answer is A.
Explanation:
Carbon dioxide is in a steel tank at 20C 10 liters and 1 atm. What is the pressure on the gas when the tank is heated to 100C?
Answer:
1.273 atm
Explanation:
We are given:
P1 = 1 atm P2 = x atm
T1 = 20 degree celsius or 293 k T2 = 100 degree celsius OR 373 k
Since the volume remains constant, we don't have to talk about that
From the Gas equation:
PV = nRT
Since number of moles (n) , Universal gas constant (R) , Volume of the gas (V) are constants
P / T = k (where k is a constant)
Hence we can say that P1 / T1 = k --------------(1)
Also, P2 / T2 = k -------------------------------------(2)
where k is the same constant
From (1) and (2):
P1 / T1 = P2 / T2
Now, plugging the values in this equation
1 / 293 = x / 373
x = 373 / 293
x = 1.273 atm
Therefore, the pressure of CO2 after increasing the temperature to 100 degree celsius is 1.273 atm
What is the freezing point of calcium?
Is calcium brittle?
Does calcium conduct electricity?
PLEASE IF YOU CAN HELP ME OUT AS SOON AS POSSIBLE IT WOULD BE MUCH APPRECIATED!!! THANK YOU!! :)
Are all atoms of an element identical and how do we know
Answer:
No, because they can each have different number of neurons but be the same element
What is the maximum kinetic energy of an ejected electron if silver metal is irradiated with 224 nm light? The
threshold wavelength for a silver metal surface is 267 nm.
Give your answer accurate to three significant figures. Use exponential notation (e.g. 1.23e-19).
Answer:The maximum kinetic energy KEe of ejected electrons (photoelectrons) is given by KEe=hf−BE KE e = h f − BE , where hf is the photon energy and BE is the binding energy (or work function) of the electron to the particular material.
Explanation:
The maximum kinetic energy of an ejected electron if silver metal is irradiated with 224 nm light is 4.66eV.
What is kinetic energy?Kinetic energy is defined as is a form of energy that an object and particle has by the reason of its movement.
It is also defined as the measure of the work that an object does by the virtue of its motion.
Kinetic energy can be expressed as
KE = 1/2 mv²
KE = hc / ∧
KE = 6.63 x 10⁻³⁴ x 3 x 10⁸ / 267
KE = 7.45 x 10⁻¹⁹ J
The charge on electrons 1.6 x 10⁻¹⁹ C
So, Maximum kinetic energy = 7.45 x 10⁻¹⁹ / 1.6 x 10⁻¹⁹
= 4.66 eV
Thus, the maximum kinetic energy of an ejected electron if silver metal is irradiated with 224 nm light is 4.66eV.
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What are some factors that affect weather?
A. altitude, topography, and latitude
B. atm pressure, wind, and temp
C. visibility, altitude, and geography
Activities that shows the nature and goals of anthropology,Sociology and Political Science
To answer the question effectively, we will talk about the key words in the question.
ANTHROPOLOGY, SOCIOLOGY AND POLITICAL SCIENCE.
ANTHROPOLOGY; This is the study of human kinds in all times and places,it also entails humanistic study which includes our prehistoric origins and contemporary human diversity as well as topics like social change,globalization,human origin and the world history.
The activities that shows the nature and goals of anthropology includes;
- Looking at ones own culture in a more objective way like an outsider.
- Discovering the things that make people more different from one another.
- Producing new theories and knowledge about human home and their behaviors.
- Discovering/finding out what all people have in common.
There are four fields of anthropology; Linguistic anthropology, Biological anthropology, Archeology and cultural anthropology.
SOCIOLOGY; This is the scientific study of human civilization.
It is systemic and studies of groups and societies that people build
and the effect these have on their behavior.
Sociology greatly focuses on various social connections,
structures, organizations, processes and institutions.
The activities that show the goals and nature of sociology includes;
- Broadening our familiarity on facts about sociology.
- Critically studying the nature of humanity.
- Exposing our minds to the diverse perspectives on attaining the truth.
- Obtaining possible theories about the society.
- Understanding and appreciating that all things in the society are interdependent with each other.
Sociology brings together inputs that are composed of frequent forms and manners,they include; view points, consolidated values, attitudes and the norms of social institutions.
The different branches of sociology are; social psychology,social organisation, applied sociology, population studies, sociological theory and research,human ecology,social change.
POLITICAL SCIENCE; This is a discipline in academics that deals with the study of political processes, institutions, governments and behaviors of people.
It studies the complex behaviors of the people in power, various political actors, such as the government administration, opposition ad the subjects which are the masses.
Anthropology, sociology and political science are areas of social science, whose main objective is to study society in historical, social and cultural contexts.
Anthropology is the science that studies the human being in depth considering biological, social and cultural aspects. Its objective is to understand the development of man in these aspects.Sociology has as its nature the study of societies, its objective is to understand the behavior of man in social formations.Political science is the science that studies the systems of government and formation of political power in society. Its aim is to better understand political institutions and their impact on society.Therefore, the social sciences seek to analyze and understand man through society, culture, economy and politics, with the aim of contributing to the development of a more egalitarian society with a better quality of life.
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