Answer:
Volume of the sulfuric acid (25cm³), same mass of each metal (1g)
Explanation:
In an experiment, the CONTROL VARIABLE also known as constant is the variable that is kept unchanged for all groups in an experiment. This is done in order not to influence the outcome of the experiment.
In this case, students are trying to investigate the reactivity of four different metals. They added 1 g of each metal to 25cm³ of sulfuric acid and recorded the temperature change. Based on the explanation of control variable above, the VOLUME OF SULFURIC ACID (25cm³) and the MASS OF EACH METAL (1g) are the CONTROL VARIABLES because they are the same or unchanged in this experiment.
why is it called the periodic table of elements (why is the word periodic in it)
Answer:
It is called "periodic" because elements are lined up in cycles or periods. From left to right elements are lined up in rows based on their atomic number (the number of protons in their nucleus). ... Each horizontal row in the table is a period. There are seven (or eight) total periods.
Explanation:
Mary is driving on a straight road. When a deer jumps in front of her, she turns her car sharply to the left. What will happen to loose objects inside the car?
Answer: The loose objects will tend to move to the right inside the car.
Explanation:
The options include:
A. The loose objects will tend to move to the left inside the car.
B. The loose objects will tend to move to the right inside the car.
C. The loose objects will tend to move toward the front of the car.
D. The loose objects will tend to move toward the back of the car.
Based on the question, we are informed that Mary is driving on a straight road and then a deer jumps in front of her, which made her turn her car sharply to the left.
The loose objects inside the car will move towards the opposite direction. Since Mary made a left turn, the loose objects in the car would move to the right.
To be effective, a certain drug must not drop below 15 mg in the body. A 120
mgs of that drug was administered to a patient. How much time will it take for that drug to reach the 15 mg minimum level. The drug's half-life is 30 minutes.(show how you arrived at your response)
Answer:
90 Minutes
Explanation:
Original concentration = 120 mg
Half life = 30 minutes
Minimum level = 15 mg
Basically, we are to calculate the time it would take to drop from 120 mg to 15 mg.
The half life of a substance is the time it takes for the original concentration of a substance to drop to half it's starting concentration.
First Half life:
Starting concentration = 120mg
Concentration after half life = 120 / 2 = 60 mg
Second Half life;
Starting concentration = 60 mg
Concentration after half life = 60 / 2 = 30 mg
Third Half life;
Starting concentration = 30 mg
Concentration after half life = 30 / 2 = 15 mg
We have reached the minimum 15 mg level. This means it took three half lives to get there.
Total time taken = No of Half lives * Half life duration = 3 * 30 mins = 90 Minutes
Meiosis goes through 2 divisions to create four unique haploid cells. true or false
Answer:
True
Explanation:
True is the ANSWER.
Question 5 (5 points)
True or False. Open clusters are groups of up to a few thousand stars that are loosely held together by gravity and
tend to appear blue.
Answer:
have a p000000000000000000
How do fossil fuels play a role in the carbon cycle?(1 point) Fossil fuels require a lot of carbon to burn, which takes carbon out of the atmosphere. Fossil fuels require a lot of carbon to burn, which releases carbon into the atmosphere. Fossil fuels are rich in carbon, and burning them releases carbon into the atmosphere. Fossil fuels are rich in carbon, and burning them returns carbon to the soil.
Answer: Fossil fuels are rich in carbon, and burning them releases carbon into the atmosphere.
Explanation:
The amount of carbon in the form of carbon dioxide in the atmosphere is about 0.03% by volume. This value is kept fairly constant by a natural process known as the CARBON CYCLE. This involves carbon dioxide being continually removed from the atmosphere by plants in photosynthesis, rain water as weak acids while in order to maintain this balance, carbon dioxide is at the same time returned to the atmosphere by:
--> burning of carbon containing substances (fossil fuel)
--> respiration of plants and animals and
--> Decomposition of organic substances.
Therefore the role of fossil fuels which are rich in carbon content releases carbon into the atmosphere when burnt.
Define "tides” in your own words.
Answer:
the rising and falling of the surface of the ocean caused twice daily by the attraction of the sun and the moon
Explanation:
Which of the following explains the VSEPR geometry of a carbon tetrachloride molecule? (5 points)
It is bent because there are four bonded pairs around carbon.
It is tetrahedral because there are four bonded pairs around carbon.
It is bent because there are two bonded pairs and two lone pairs around carbon.
It is tetrahedral because there are two bonded pairs and two lone pairs around carbon.
Answer:
(B) It is tetrahedral because there are four bonded pairs around carbon
Explanation:
CCl4 means four chloride ions bonded covalently with single carbon.
its coordination figure is:
CF = 1/2(Vallence of central atom + electrons donated from substituents - charge)
CF = 1/2(4 + 4.1 - 0)
CF = 4
Bond electrons = 4
Lone pair electrons = 0
Hence, CCl4 is tetrahedral
How many moles are 21.67 L of NH4CI?
Type your answer...
Answer:
0.967mole
Explanation:
Given parameters:
Volume of NH₄Cl = 21.67L
Unknown:
Number of moles = ?
Solution:
We assume that the volume was taken at standard temperature and pressure,
Then;
Number of moles = [tex]\frac{volume }{22.4L}[/tex]
Number of moles = [tex]\frac{21.67}{22.4}[/tex] = 0.967mole
Which is a property of potassium (K)?
A. It is dull and brittle.
B. It is extremely reactive.
C. It is not reactive.
D. It is white and hard.
Answer:
B: It is extremely reactive
Explanation:
Potassium metal is also soft and white with a silvery lustre, has a low melting point, and is a good conductor of heat and electricity.
Answer: Properties, occurrence, and uses. Potassium metal is soft and white with a silvery lustre, has a low melting point, and is a good conductor of heat and electricity. Potassium imparts a lavender colour to a flame, and its vapour is green.
Explanation: hope it helps
Consider the diagram. Top: A ball is shown traveling left to right toward an identical stationary ball. Middle: the first ball hits the second ball. Bottom: The right-hand ball travels to the right away from the left-hand ball, which is now stationary.
Which postulate of the kinetic-molecular theory best describes the event in the diagram?
Most of the volume of a gas is empty space.
All collisions between particles are perfectly elastic.
There is no force of attraction or repulsion between gas particles.
The average kinetic energy of particles depends only on temperature.
Answer:
All collisions between particles are perfectly elastic
Explanation:
found it somehwere else
The statement, that describes postulate of the kinetic-molecular theory is "all collisions between particles are perfectly elastic."
What is collisions?A collision would be any process where two or even more objects exert forces on one another quickly.
What is kinetic-molecular theory?The kinetic-molecular theory explains matter states and is based on the assumption that matter is made up of small particles that are always in motion. It is a simple, historically significant classical model of the thermodynamic behavior of gases that established several fundamental thermodynamic ideas.
Because the molecules are so small, the kinetic theory of gases assumes that the collision between them is fully elastic. Because the molecules are so small, their energy and momenta are conserved during collisions. As a result, regardless of collisions, the temperature remains constant.
Hence the correct option is all collisions between particles are perfectly elastic.
Learn more about kinetic theory of gases here
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a sample of methane gas at a pressure of 0.727 atm and a temperature of 26.9 occupies a volume of 726 ml. if the gas is allowed to expand at constant temperature until its pressure is 0.412 atm, the volume of the gas sample will be _ mL
Answer:
1280L
Explanation:
Given parameters:
Initial pressure = 0.727atm
Temperature = 26.9°C
Initial volume = 726mL = 0.726L
New pressure = 0.412atm
Unknown:
New volume of the gas sample = ?
Solution:
To solve this problem, we apply boyles law;
P1V1 = P2V2
P and V are pressure and temperature
1 and 2 are initial and new state
0.727 x 0.726 = 0.412 x V2
V2 = 1.28mL = 1280L
What is the percent composition of nitrogen in N 2 O
Answer:
63.6%
Explanation:
The given compound is:
N₂O;
The problem here is to find the percent composition of nitrogen in the compound.
First find the molar mass of the compound:
Molar mass of N₂O = 2(14) + 16 = 44g/mol
So;
Percentage composition of Nitrogen = [tex]\frac{2 x 14}{44}[/tex] x 100 = 63.6%
Why do strong storms such as hurricanes usually result in large ocean waves?
A) Hurricanes produce a lot of rain that ends up in oceans
B) A lot of small earthquakes happen during hurricanes
C) Strong winds are produced during hurricanes
D) Hurricanes stir up the ocean floor
Answer:
C
Explanation:
so the way that waves are created normally is by slight breezes the stronger the breeze the bigger the wave so if strong winds are produced it will result in large waves
Hope this helped you and check out my YT my most popular video at Ryetube ExTrEmE
Which statement describes the motion of the sun?
The sun rotates at the same rate throughout.
The sun does not rotate at its poles.
Different parts of the sun rotate at different rates.
The sun does not rotate at its equator.
Answer: Different parts of the sun rotate at different rates.
Explanation:
The statement that best describes the motion of the sun is that different parts of the sun rotate at different rates.
First and foremost, we should note that the rotation of the sun is on its axis and also the sun isn't a solid. Due to this, its motion will be that there'll be rotation of different part of it at different rates. Assuming the sun was solid, then all of its parts will move together.
Answer:
Different parts of the sun rotate at different rates.
Explanation: pic proof
Plss answer the question in the picture.
What energy transform occurs when the hot plate is plugged into the outlet and the control knob is on position?
Thermal to mechanical
Thermal to electrical
Electrical to thermal
Mechanical to thermal
Answer:
Its electrical to thermal energy
Explanation:
2
What is the relationship between an animal's brain and its ability to learn and modify behaviors?
A. Animals with less complex brains have a greater capacity to learn.
В.
There is no relationship between an animal's brain and its ability to learn.
C.
Animals with brains have no capacity to learn or modify behaviors.
D
Animals with more complex brains have a greater capacity to learn.
Reset
Submit
Answer: D . Animals with more complex brains have a greater capacity to learn.
Explanation:
The different parts of the brain are responsible for distinct processes like thinking, control of behavior, learning, reasoning, speech, emotions, muscle movements, controls balance, and others. This aids in the fact that complex the brain more different functions it can perform. The large brain size as well as volume is associated with better cognitive functions along with complexity. The specific regions of the brain that can be correlated with the volume as well as intelligence are temporal, parietal and frontal parts of the brain in animals and in humans.
what is the concentration of a solution which is 2g in 150cm3 in g/dm3
Answer:
13.33 g/dm³
Explanation:
Concentration (g/dm³)= mass(g) ÷ volume (dm³)
Now you need to convert 150 cm³ to dm³
1000cm³ = 1 dm³
thus, 150 cm3= 150 ÷ 1000
= 15dm³
and you already have mass in grams
so concentration = 2 ÷ 0.15
= 13.33 g/dm³ and there you go.. solved ;)
A remnant or trace of an organism from the past is called a
Answer:
a fossil
Explanation:
Answer:Fossil
Explanation:A remnant or trace of an organism of a past geologic age, such as a skeleton or leaf imprint, embedded, and preserved in the Earth's crust, usually in stratified rock.
Identify one trait in a plant that could be changed with selective breeding and explain how the change would be useful? Science. I will give brainliest to people who answer correctly
Write the name for the IONIC compound that contains two aluminum atoms and three sulfur atoms. (Need help ASAP)
Mark and Amanda conduct the same investigation as Nguyen, but they use four rocks. They test the same three rocks as Nguyen but add one more rock that has the same color and density as limestone. However, the rock doesn't produce bubbles when acid is added to it. Explain how the mineral composition of this rock compares with that of limestone?
Answer:
The Rock does not contain carbonate in it.
Explanation:
Limestone(CaCO_3) when reacts with a acid produces carbon dioxide, which comes out as bubbles in the solution. It means the 4th rock does not have carbonate in it. Carbonate minerals are unstable in contact with hydrochloric acid. When acid begins to effervesce (fizz) on a specimen. These bubbles confirms the presence of carbonate in mineral.
Answer:
no,exept y and z are similar
Explanation:
litterly what it says '-'
How to calculate the mass of the sulfur (VI) oxide molecule
Explanation:
If you look back at the formula ( SO2 ), you can see that there is one sulfur and two oxygens present. Therefore, the molar mass of sulfur dioxide is [1 × 32.1 + 2 × 16.0] = 64.1 g/mol.
In general, what happens to atoms when they are exposed to extreme temperatures?
Answer:
When heat is added to a substance, the molecules and atoms vibrate faster. As atoms vibrate faster, the space between atoms increases. The motion and spacing of the particles determines the state of matter of the substance. ... Solids, liquids and gases all expand when heat is added.\
so hope that helps and sooooo
Answer:
When heat is added to a substance, the molecules and atoms vibrate faster. As atoms vibrate faster, the space between atoms increases. The motion and spacing of the particles determines the state of matter of the substance. ... Solids, liquids and gases all expand when heat is added.
A solution is a mixture where one substance is dissolved in another. One example of a solution is salt water. Why does salt water appear to be a single substance even though it contains more than one substance? A. Each component in salt water retains its original physical properties. B. The components in salt water cannot be separated from each other. C. The particles in salt water are spread throughout. D. Salt water is a solution and also a pure substance.
Answer: C. The particles in salt water are spread throughout.
Explanation:
Homogeneous mixtures: It is a mixture that has uniform composition throughout the solution and the particle size or shapes are not different. There is no physical boundary between the dispersed phase and dispersion medium. Example: Salt dissolved in water.
Heterogeneous mixtures: It is a mixture that has non-uniform composition throughout the solution and the particle size or shapes are also different. There is a physical boundary between the dispersed phase and dispersion medium. Example: sand in water.
Answer:
Its c
Explanation:
A solution is a mixture where one substance is dissolved in another. One example of a solution is salt water. Why does salt water appear to be a single substance even though it contains more than one substance. Got it right in school city
idoine would have chemical properties most like ?
An element's atoms are exactly the same - no matter where that element is found.
A.True
B.False
Answer:
B. False
Explanation:
All the atoms of an element are not entirely the same no matter where they are found.
The phenomenon of isotopy brings a different perspective to the identity of an element.
Isotopy is the existence of two or more atoms of the same element having the same atomic number but different mass numbers due to the differences in the number of neutrons in their various nuclei. Isotopes of an element have the same electrons but differ in their masses. They also differ in their chemical properties.Will mark the brainiest later for correct answers! Please show work.
Mass C12H22O11 = 14.08g
Convert grams to moles:
Convert grams to molecules:
Mass NaCI: 17.75g
Convert grams to molecules:
Convert grams to formula units:
Copper (II) Sulfate Pentahydrate
Chemical Formula: CuSO4.5H2O
Mass: 20.06g
Convert grams to moles:
Formula Units:
Answer:
According to avogadro's law, 1 mole of every substance contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles and weighs equal to its molecular mass.
To calculate the moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}[/tex]
[tex]\text{Number of moles}=\frac{\text{Given molecules}}{\text {Avogadros number}}[/tex]
a. moles in 14.08 g of [tex]C_{12}H_{22}O_{11}[/tex] = [tex]\frac{14.08g}{342.3g/mol}=0.04113moles[/tex]
molecules in 14.08 g of [tex]C_{12}H_{22}O_{11}[/tex] = [tex]0.04113\times 6.023\times 10^{23}=0.2477\times 10^{23}[/tex]
b. moles in 17.75 g of NaCl = [tex]\frac{17.75g}{58.5g/mol}=0.3034moles[/tex]
molecules in 17.75 g of [tex]NaCl[/tex] = [tex]0.3034\times 6.023\times 10^{23}=1.827\times 10^{23}[/tex]
formula units 17.75 g of [tex]NaCl[/tex] = [tex]0.3034\times 6.023\times 10^{23}=1.827\times 10^{23}[/tex]
c. moles in 20.06 g of [tex]CuSO_4.5H_2O[/tex]= [tex]\frac{20.06g}{249.68g/mol}=0.08034moles[/tex]
formula units in 20.06 g of [tex]CuSO_4.5H_2O[/tex]= [tex]0.08034\times 6.023\times 10^{23}=0.4839\times 10^{23}[/tex]
Covalent bonds can be single, double, or triple.
How many electrons are shared in a molecule, like O2 that has a double bond?
4
6
12
2