Answer: i’m pretty sure it’s B
Explanation:
2H2+O2→2H2O
There are four atoms of hydrogen (H) before the reaction. How many atoms of hydrogen are present after the reaction?
4
8
5
2
Answer:
2
Explanation:
The number of atoms of hydrogen that are present after the reaction is 4. The correct option is the first option - 4
Law of conservation of massFrom the question,
We are to determine the number of atoms of hydrogen present after the reaction.
From the law of conservation of mass which states that
"Matter can neither be created nor destroyed"
This means, the number of atoms are the same before and after the chemical reaction.
Since the number of hydrogen atoms before the reaction is four, then there would be four hydrogen atoms after the reaction.
Hence, the number of atoms of hydrogen that are present after the reaction is 4. The correct option is the first option - 4
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One of the major ways humans depend on marine plants is for which of the following?
A.) Production of oxygen
B.) Regulation of ocean temperature
C.) Increasing atmospheric carbon dioxide
D.) Maintaining the concentration of salt
Matter are anything that is made up of atoms. The quantity of matter can be observed only on the basis of mass and volume calculation. Therefore, the correct option is option A.
What is matter?Matter is a substance that has some mass and can occupy some volume. The matter is mainly used in science. Matter can be solid, liquid or gas.
Matter is anything that is made up of atoms. Anything around us that can be physically seen and touched are matter. Ice, water and water vapors are example of matter.
So as we saw that matter has some mass so mass can be measured in gram only. Mass can also be represented as number of molecules. We also saw that matter occupy some volume and that volume is measured only in liter. Oxygen is the only thing for which humans depend on marine plants. Oxygen is very important for humans.
Therefore, the correct option is option A.
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A person throws a ball up into the air, and the ball falls back toward Earth. At which point would the kinetic energy be the lowest?(1 point)
A)when the ball is at its highest point
B) at a point when the ball is still rising
C)when the ball leaves the person’s hand
D) at a point before the ball hits the ground
When a person throws a ball up into the air, and the ball falls back toward Earth, the kinetic energy will be the lowest when the ball is at its highest point (option A).
Kinetic energy is given by:
[tex] K = \frac{1}{2}mv^{2} [/tex]
Where:
m: is the mass
v: is the velocity
So, the kinetic energy is proportional to the velocity and the mass of the object.
When the person throws the ball up into the air, the ball will move upward to a maximum height and then will move down until it hits the ground.
In the upward motion, the ball's velocity will decrease until it reaches the maximum height, where it will be zero. In the downward motion, the magnitude of the ball's velocity will increase because of the acceleration due to gravity until it reaches the ground.
From the statements:
A) When the ball is at its highest point, the velocity will be zero, so the kinetic energy will be zero.
B) When the ball rises, the velocity decreases, so the kinetic energy will also decrease.
C) When the ball leaves the person's hand, it has an initial velocity that is the highest, so the kinetic energy has at this point, the maximum value.
D) Before the ball hits the ground, the ball's velocity has the same value (in magnitude) as the initial value (when the ball leaves the person's hand), so the kinetic energy will be the highest at this point (like statement C).
Therefore, the kinetic energy will be the lowest when the ball is at its highest point (option A).
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10 points Explain the Lunar Eclipse in 4-5 (PLEASE DON'T LOOK IT UP THAT'S PLAGIARIZING
Answer:
use code sypherpk
Explanation:
Does stirring a liquid make it cool down faster?
Answer:
Stirring will help cool a hot drink because it speeds up the process of convection by bringing the hottest liquid at the bottom to the top
Explanation:
Answer: No not really, all your doing is moving it around
Explanation:
I tested it
The combination
nation of two or more atoms from same or different elements creates a(n)
An atom of tin has an atomic number of 50 and a mass number of 119. How many protons, electrons, and neutrons are found in one neutral atom of tin?
A.50 protons, 69 electrons, 50 neutrons
B.50 protons, 50 electrons, 69 neutrons
C.69 protons, 50 electrons, 69 neutrons
D.69 protons, 69 electrons, 50 neutrons
HELP ME PLEASE I REALLY NEED HELP EXPLAIN IN YOUR OWN WORDS SHOW WORK PLEASE
Be sure to show your work and explain how you got your answer.
Answer: Y M C A DODODODO Y M C A
i rlly just wanted to do that. sry i wasted ur time
Explanation:
Describe one example of an energy transformation in this diagram and explain why it is a transformation. Repeat this description and explanation for an energy transfer.
Answer:
energy is just we all know that energy is the ability too do work
as given in example below
Explanation:
we move
we walk
draw
we push
we pull
these all thiings called Energyy
Which statements are true?
All landforms have the same combinations of elevation and relief.
Different landforms have different combinations of elevation and relief.
Elevation is the height of a feature above sea level.
Relief is the height of a feature below sea level.
Relief is the difference between the highest and lowest points in an area.
Gold atoms can be identified based on the number of which subatomic particles?
A.neutrons
B.electrons
C.nuclei
D.protons
Answer: A
Explanation:
A Gold (Au) atom has 79 protons and 79 electrons. A typical gold atom has 118 neutrons, though there are 18 other radioisotopes discovered so far. 79 is its charge (atomic number), which is both its proton number and electron number
Why were the iron fillings in a water a suspension?
please help!!!!!!!!!!!!!!!!!!!!!1
Steve fills a jar with water and adds Epsom salts and ammonia. After five minutes, he observes that white particles have formed and settled at the bottom of the jar. Steve is unable to change these particles back to any of the three original substances by heating or stirring the solution. He isolates the white particles and finds that they have properties that are very different from any of the three starting materials. Which statement BEST explains Steve's observation?
Group of answer choices
A physical change occurred because no color change was observed.
A chemical change occurred because a new substance formed.
A physical change occurred because stirring did not change the solution.
A chemical change occurred because a solid substance formed.
A student pot acabe of better on a metal rod. Then be placed the other end of the red in a beaker of hot water. The setup for the investigation is shown below
The butter melted in ten minutes. What type of energy did the metal rod conduct to the butter?
electrical
chemical
thermal
mechanical
A student looking for an element that will bond with sodium (Na) knows that table salt is a compound of sodium and chlorine (Cl). Based on this information, which of the following elements would MOST likely bond with sodium?
A.argon (Ar)
B.bromine (Br)
C.calcium (Ca)
D.potassium (K)
According to the concept of electronic configuration and valency sodium is most likely to bond bromine.
What is electronic configuration?Electronic configuration is defined as the distribution of electrons which are present in an atom or molecule in atomic or molecular orbitals.It describes how each electron moves independently in an orbital.
Knowledge of electronic configuration is necessary for understanding the structure of periodic table.It helps in understanding the chemical properties of elements.
Elements undergo chemical reactions in order to achieve stability. Main group elements obey the octet rule in their electronic configuration while the transition elements follow the 18 electron rule. Noble elements have valence shell complete in ground state and hence are said to be stable.
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If it rained, what would be the deepest layer the water would go through?
Answer:
soil
Explanation:
Which of the following happens to a material when it goes through a chemical change?
A The substance changes size.
B The substance changes state.
C The substance changes shape.
B The substance changes into a new substance.
The following happens to a material when it goes through a chemical change is the substance changes into a new substance. Thus option D is correct.
What is chemical change?Chemical change is defined as a change of materials into another, new materials with different properties and one or more than one new substance are formed.
Physical change is defined as a type of change in which the form of matter is altered but one substance is not transformed to another substance i.e. new substance is not formed.
Thus, the following happens to a material when it goes through a chemical change is the substance changes into a new substance. Thus option D is correct.
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Correctly sequence the following from smallest to largest in mass: protons, atom, electrons.
Answer:
Electrons, protons, and then atoms
Explanation:
Yea...
scientific investigation starts with an observation of a natural phenomenon or problem, what observation prompted the family to conduct a scientific investigation? (please need help)
A scientist is studying a compound that includes nitrogen, carbon, oxygen, and hydrogen. Is the scientist studying an organic molecule? Why or why not?
Answer: It is an organic molecule
Explanation:
In order for a molecule to be organic, it has to contain both carbon and hydrogen. The compound that the scientist is studying contains both.
A. On the Periodic Table of Elements, columns are called ______________________; all of these
elements
have the same number of ___________________________.
B. On the Periodic Table of Elements, rows are called _____________________; all of these have the same
number of __________________________.
On the Periodic Table of Elements, columns are called groups ,all of these elements have same number of valence electrons and the rows are called periods and have same number of valence shells.
Periodic table is a tabular arrangement of elements in the form of a table. In the periodic table, elements are arranged according to the modern periodic law which states that the properties of elements are a periodic function of their atomic numbers.
It is called as periodic because properties repeat after regular intervals of atomic numbers . It is a tabular arrangement consisting of seven horizontal rows called periods and eighteen vertical columns called groups.
Elements present in the same group have same number of valence electrons and hence have similar properties while elements present in the same period show gradual variation in properties due to addition of one electron for each successive element in a period.
Thus, columns are called groups ,all of these elements have same number of valence electrons and the rows are called periods and have same number of valence shells.
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Buying fruit and vegetables needs to be done more often as these types of foods can quickly go rotten. What could you do to slow down the chemical change of fruits and vegetables rotting? Give a reason to support your answer.
Answer:
putting them in the fredge while in a plastic container
Explanation:
my reason is the cools down / kinda freeze the chemicals so it slows down
A green box contains a blue box and a pink box. The blue box contains C H subscript 4 + 2 O subscript 2. An arrow then leads in the green box to the pink box, which says C O subscript 2 + 2 H subscript 2 O. Lines lead from labels to parts of the boxes. Label A leads to the beginning of the green box. Label B leads to the + in the blue box. Label C leads to the arrow. Label D leads to the 2 in 2 H subscript 2 O. Label E leads to the end of the pink box.
Identify each part of this chemical equation that describes the burning of methane and oxygen.
B (blue box):
D (number):
E (purple box):
Answer:
A (the entire green box):
✔ chemical equation
B (the blue box):
✔ reactants
C (the arrow):
✔ reacts to form
D (the number):
✔ coefficient
E (the purple box):
✔ products
Answer:
A chemical equation
B reactants
C reacts to form
D coefficient
E products
Explanation:
hope this helps, the person above me is also correct
After studying chemical reactions in school, Jen examined some of the different ways people use synthetic materials. She found that there are a variety of ways people use them. What are some of the ways people use these materials and why?
Please help out
1) a cold air mass and meets warm air mass. what will happen, in terms of the difference in their densities?
2) archie needs to find the density of an intricately crafted crown, to see if it is pure gold. he has no trouble measuring mass, but he doesnt know what to do next. what should he do?
I NEED HELP PLEASEEE
Which phrase provides the best definition of a landform region?
A a large area where the topography contains the three main landforms
B the border where two different landforms meet
a large area where the topography is made up of one landform
C a large area where the topography is inconsistent and contains multiple landforms
Answer:
a large area where the topography is made up of one landform.
Eriq, a chemist, is running tests with four unknown elements. He has found that they all bond the same way, so he knows that they are in the same group on the periodic table of elements. The table shows other properties that Eriq observed.
A 4-column table with 4 rows titled properties of four unknown elements. The first column titled element number has entries 1, 2, 3, 4. The second column titled melting point has entries 266 K, 172 K, 387 K, 53 K. The third column titled boiling point has entries 332 K, 239 K, 457 K, 85 K. The fourth column titled phase at room temperature has entries liquid, gas, solid, gas.
These four elements are most likely in group
15.
16.
17.
18.
Answer:17
Explanation:
i agree
what coeiffecents need to be added to balance to balance the chemicial equation Na+02 arrow NaO2
Answer:
#4 - 4, 1, 2
Explanation:
4Na + 1O2 => 2Na2O
What is the main difference between a chemical and a physical change? Use examples to support your answer.
Answer:
Physical changes are usually about physical states of matter. Chemical changes happen on a molecular level when you have two or more molecules that interact. Chemical changes happen when atomic bonds are broken or created during chemical reactions.
Explanation:
Example of an chemical reaction: explosion
Example of an physical reaction: Ice melting
Plz put me in the brain list
Examples of physical changes are freezing, melting(melting of ice cubes).
Examples of chemical changes are combustion, rusting of iron.
A physical change is a change that alters the physical properties of matter particularly the form and state. In many cases, the change is easily reversible. Examples are freezing, melting(melting of ice cubes). A chemical change is a change in which a new kind of matter is formed. It is always accompanied by energy changes which can either be evolution or absorption of heat or light or both. The process is not reversible. Examples are combustion, rusting of iron, precipitation, e.t.c. An example of chemical change which we see in our daily life is the conversion of milk to curd.
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Buying fruit and vegetables needs to be done more often as these types of foods can quickly go rotten. What could you do to slow down the chemical change of fruits and vegetables rotting? Give a reason to support your answer.
The process used to slow down the chemical change of fruits and vegetables is refrigeration.
What is refrigeration?Refrigeration is defined as the process of removing heat from an enclosed space and surface for the purpose of lowering the temperature.
It can also be defined as removal of unwanted heat from the selected object, substances or space and its transferred to another object or substance.
Keeping the fruits and vegetables in refrigerator will help to slow the growth of bacteria and slow down the rotting of fruits and vegetables.
Thus, the process used to slow down the chemical change of fruits and vegetables is refrigeration.
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