chemical reaction occurs when the chemical identity of the reactants is different from that of the products. A new substance forms with different properties from the original react
Evidence that a chemical reaction has occurred can be a color change, light formation, gas bubbles formation, precipitate formation, or temperature change,
Use the following information to answer question 1.
QUESTION 1
Instant cold packs consist of ammonium nitrate and water. When the two are mixed, the temperature changes and becomes colder. It is described using the chemical equation
NH4NO3(s) → NH4+ (aq) + NO3(aq)
LA
Is this an example of an endothermic or exothermic reaction? Why?
Answer:
Explanation:
Exothermic: the surrounds feel warmer. A wood fire stove is a good example of an exothermic reaction. You can feel the heat on your hands. It's exothermic.
Endothermic is exactly the opposite. The reaction takes place, but the heat comes from the surroundings. When you touch something that goes through an endothermic reaction, it feels much cooler.
This reaction, just by definition is endothermic.
True or False? The energy carried by a sound
wave is blocked by collisition
between the particles in the
material the name is traveling
in
Answer:
true
Explanation:
i checked on moogle
What is the significance of cell division?
A. to make ATP
B. to prevent replication
C. to repair and replace other cells
D. to make glucose
What is the final concentration (M) of a solution prepared by diluting 50.0 mL of a solution to a volume of
What are some examples of a physical change? (list more than 2 examples)
Answer:
Examples of physical change include changes in the size or shape of matter. Changes of state, for example, from solid to liquid or from liquid to gas, are also physical changes. Some of the processes that cause physical changes include cutting, bending, dissolving, freezing, boiling, and melting.
Explanation:
I hope this helps
why are earthquakes different in New Madrid than in California.
9. Name the element which has the following numbers of particles:
I
A. iron
B. iodine
C. Helium
D. calcium
E. lead
F. hydrogen
check your periodic table to see if they are correct
atomic number, proton number and electron are the same
to find neutron = mass number - atomic number
How does the weather caused by a warm front compare to the weather caused by a cold front?
A: A warm front brings fog, but a cold front brings clouds that form from dry air.
B: A warm front brings rapid changes in weather, but a cold front brings slow changes in weather.
C: A warm front brings widespread cloud cover, but a cold front brings intense sun coverage.
D: A warm front brings rain in humid air on occasion, but a cold front brings thunderstorms in summer.
Answer:
The weather caused by a warm from and a cold front compare by:
D. A warm front brings rain in humid air on occasion, but a cold front brings thunderstorms in summer.
A warm front is a phenomenon in which a warm air mass replaces a cold air mass, creating fog and rain on one occasion. While the cold front is the replacement of a warm air mass by a cold air mass changing the pressure and creating a thunderstorm in the middle of summer. The warm front happens in zones close to the equator and the cold fronts happen in almost every place.
Hope that helps. x
Which of the following has mass?
A. Space
B. Light
C. Matter
Ο Ο
D. Force
Answer:
matter should be the answer
Explanation:
Hope this helps!
Answer:
matter because matter makes up everything in the world EVERYTHING like this computer ri am typing on? matter. what ever device you are using to view this? matter. everything is made of matter. matter is starting to sound weird now so I'm gonna stop saying it and this is the end of the answer remember THAT ANSWER IS MATTERR!!!!!
Large networks of ators covalently bonded together are called:
a) Giant covalent structures
b) Molecular structures
c) Giant ionic lattices
d) Superconductors
Answer:
Giant Covalent Structures, Diamond and Graphite are giant covalent structures since they're allotropes of Carbon.
Answer:
Giant covalent structures contain very many atoms. , each joined to adjacent atoms by covalent bonds. The atoms are usually arranged into giant regular lattices - extremely strong structures because of the many bonds involved.
Why do some atoms form chemical bonds while others do not?
Answer:
Atoms of these elements have full outer electron shells. These atoms are stable and very rarely form bonds with other atoms. If the electronegativity values between two atoms are comparable, they may still form chemical bonds to increase the stability of their valence electron shell
Explanation:
What is Nuclear fusion
Answer:
Nuclear fusion is a reaction in which two or more atomic nuclei are combined to form one or more different atomic nuclei and subatomic particles (neutrons or protons).
When heat is being transferred away from a substance, the resulting phase change graph is known as a ____ curve.
a. Cooling
B. Heating
Write the shape of s and p-orbials.
s-orbitals are spherical, while p-orbitals are similar to a 3-D infinity symbol. I have attached an image of the comparison.
hydrofluoric acid
What’s the formula
Hydrofluoric acid/Formula
______________________
HF
______________________
o0o0o0o0o0o0o0o0o0o0o0
If 48.3g of iron is completely rusted in oxygen to produce 62.5g of iron (III) oxide, how many grams of oxygen are involved in the reaction?
The amount of oxygen involved in the reaction would be 20.7 g
The equation of rusting of iron is as follows:
[tex]4Fe + 3O_2 ---> 2Fe_2O_3[/tex]
The mole ratio of Fe to O2 is 4:3.
Mole of 48.3 g Fe = mass/molar mass
= 48.3/56
= 0.8625 moles
Equivalent mole of O2 = 0.8625 x 3/4
= 0.6469 moles
Mass of 0.6469 moles O2 = mole x molar mass
= 0.6469 x 32
= 20.7 g
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I know the answer is A/1 but I’m not sure how to explain it, I would like some help on the explanation part
3. The accompanying diagram represents a cell in water. Formulas of molecules that can move freely across the cell membrane are shown. Some molecules are located inside the cell and others are in the water outside the cell.
(Picture) diagram
Based on the distribution of these molecules, what would most likely happen after a period of time?
A. The concentration of O₂ will increase inside the cell.
B. The concentration of CO₂ will remain the same inside the cell.
C. The concentration of O₂ will remain the same outside the cell.
D. The concentration of CO₂ will decrease outside the cell.
Answer:
number one is the correct option
Like the success of animals, the success of plants is limited based on the resources available to each individual. In the tropical
rainforest, plants are especially limited by the spate they have available to grow and reproduce. Which of these statements
describes a way that limited space will impact
the success of a plant in the rainforest? (SC.7.L.17.3)
A plant without enough space will face increased predation from herbivores
a
O A plant without enough space will not have as many parasites and diseases.
3
A plant without enough space will be more likely to be impacted by air quality
A plant without enough space will not be able to capture enough light to grow.
A plant without enough space to grow may be impacted by inadequate air as well as light for proper growth.
The competition for space in the tropical rainforest has impacts on two processes:
Light for photosynthesisAir for growthLight is very important for photosynthesis and the overall well-being of plants. In a tight space, light and air become limited. This means that plants growing in such a space will not be able to photosynthesize optimally.
Plant roots need air to function properly and when becomes inadequate, the entire plant becomes negatively impacted.
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What do you already know about gases?
Answer:
gasese molecules are always in free state
Please what the element it is
Answer:
Helium
Explanation:
One electron shell is shown in the model of Helium drawn by Bohr, and it has two electrons inside of it. The atomic number of helium is 2, so the number of protons and electrons that can be used to make its Bohr diagram is the same as its number.
(b) at 400k both compounds are gases. at this temperature, which compound, ch4(g) or ccl4(g), behaves more like an ideal gas? justify your answer, including reasoning about both molecules.
CH4 has more ideal gas behavior than CCl4 due to its higher intermolecular interaction.
We must note that ideal gases have minimal interaction with each other. Hence, in deciding which gas has ideal gas behavior, we have to consider the gas that has the least degree of intermolecular interaction.
However, the both gases contain nonpolar molecules but CCl4 has a greater molecular mass and has more intermolecular interaction than CH4 hence CH4 has greater ideal gas behavior than CCl4.
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When potential energy is converted into kinetic energy, some of that energy is always in the form of:
А.
light energy
B.
chemical energy
с
nuclear energy
D
heat energy
In an investigation that uses the scientific method, which step immediately follows making a hypothesis?
summarizing the results
asking a question
making observations
designing an experiment
C????
Answer:
The answer is designing an experiment
Explanation:
Since we already have a hypothesis, we need to test the hypothesis and this is done by designing an experiment that will do this test.
2. The two naturally occurring isotopes of hydrogen are hydrogen-1 ( 1.00783 amu; 99.9885 percent) and hydrogen-2 (2.01410 amu; 0.0115 percent). What is the average atomic mass of hydrogen?
A. 1.0079 amu
b. 1.0097 amu
c. 1.0309 amu
D. 1.5110 amu
Answer:
1.0079 g/mol
Explanation:
99.989% / 100% = 0.99989 hydrigen-1 , 0.0115% / 100% = 0.000115 hydrogen-2
0.99989 x 1.0078 = 1.0077 , 0.000115 x 2.0141= 0.000232
1.0077 + 0.00023
Answer: 1.0079
cellus
A student measures the acidity of a solution and
concludes that it has a pH of 2.70. However, the
seller claims that its pH is 3.20. What is the
percent error in the student's measurement?
Answer:
15.63%
Explanation:
The formula of error percentage is:
([experimental value-real value]/real value)100%
You divide the subtraction of the absolute value of experimental value (the one you got during a experiment) and the one that's "proven" to be right by again, the proven value. You got a decimal and all you have to do is multiply it by 100%
Answer:
on acellus the answer is 16%
I hate acellus
Explanation:
how many moles of copper are there in 6.93 g of copper sample
pls be quick
[tex]\\ \sf\longmapsto No\:of\;moles=\dfrac{Given\:mass}{Molar\:mass}[/tex]
[tex]\\ \sf\longmapsto No\:of\:moles=\dfrac{6.93}{63.5}[/tex]
[tex]\\ \sf\longmapsto No\:of\:moles=0.109\approx 1.11moles[/tex]
Explain the reason that maps must change over time
Explanation:
Because the place on the map can be changed to another shape by natural effects like faulting,folding , volcanism
Answer:
Maps must change over time as the geographical structures change from time o time. The roads and highways also change often due to the development activities .
. A sample of ammonium phosphate can be prepared by the reaction of aqueous ammonia and phosphoric acid. 3NH3 (aq) + H3PO4 (aq) (NH4),PO4 (aq) 25.0cm of 1.25 mol/dm phosphoric acid is neutralised by 45.3cm of aqueou ammonia (a) Calculate the concentration in mol/dm3 of the ammonia used.
The concentration in mol/dm³ of the ammonia used is 2.07 mol/dm³
Balanced equation3NH₃ (aq) + H₃PO₄ (aq) -> (NH₄)₃PO₄ (aq)
From the balanced equation above,
The mole ratio of the acid, H₃PO₄ (nA) = 1The mole ratio of the base, NH₃ (nB) = 3How to determine the molarity of NH₃ Volume of acid, H₃PO₄ (Va) = 25 cm³Molarity of acid, H₃PO₄ (Ma) = 1.25 mol/dm³Volume of base, NH₃ (Vb) = 45.3 cm³ Molarity of base, NH₃ (Mb) = ?MaVa / MbVb = nA / nB
(1.25 × 25) / (Mb × 45.3) = 1 / 3
31.25 / (Mb × 45.3) = 1 / 3
Cross multiply
Mb × 45.3 = 31.25 × 3
Divide both side by 45.3
Mb = (31.25 × 3) / 45.3
Mb = 2.07 mol/dm³
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Suppose you have samples of three unknown solids. Explain how you could use their properties to determine whether or not they are ionic solids.
Given a sample of three unknown solids, we would be able to deduce which are ionic solids by their melting and boiling points, conductivity in water, and the insulation they provide.
What are Ionic solids?An ionic solid is a solid formed by ionic bonds. They are the solid version of ionic compounds, which are held together by strong electrostatic energies. What properties do they possess?Among their many properties, ionic solids possess high melting and boiling points.These solids are also known to conduct electricity well when dissolved into water, however, this can be tested after melting them as they will not conduct electricity in a solid state.A final property that we can use to identify them is that they provide a good means of insulation.Each of these properties can be tested and will allow us to determine the ionic solids amongst the samples.Therefore, we can find the ionic solids amongst the samples by testing their melting and boiling points, conductivity in water, and the insulation they provide, given that each of these should provide high values to indicate an ionic solid.
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what natural resources are used to make plastic bags
Answer:patrolieum
Explanation: