Answer:
b. a new gas is observed in the form of bubbles
Explanation:
The only statement that was evidence of a chemical reaction is a new gas is observed in the form of bubbles Any time a new substance is created, a chemical reaction has taken place.
Is a tooth made out of matter or not matter?
Human teeth are made up of four different types of tissues.
What is the energy of a photon that emits a light of frequency 7.21 x 1014 Hz? A. 4.78 x 10-19 J B. 2.76 x 10-19 C. 1.0910-19 J D. 4.16 x 10-19 J
Answer:
E = 4.78×10^−19 J
Explanation:
The chemical equation for the energy of a photon is given by:
E =hν , where h is the Planck constant and ν is the frequency.
E =hν = 6.626×10^−34 Js × 7.21×10^ 14
s−1 = 4.78 × 10^−19 J
Answer:
A. 4.78 x 10-19 J
Explanation:
A P E X
Sodium chloride (NaCl) is formed in a chemical reaction between sodium (Na) and chlorine (Cl2).
What is sodium chloride?
14.
A.
an element
B.
a mixture
C.
a compound
D.
an atom
According to collision and transition state theories, what is the importance of activation energy?
According to the collision theory, the following criteria must be met in order for a chemical reaction to occur: Molecules must collide with sufficient energy, known as the activation energy, so that chemical bonds can break.
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Collision theory expresses that substance responses (in the gas stage) happen because of crashes between reactants.
Importance of activation energy:To really start a reaction, impacts should be adequately lively (dynamic energy) to break compound bonds; this energy is known as the Activation energy. As the temperature rises, atoms move quicker and impact all the more energetically, significantly improving the probability of bond breakage upon crash.
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What can we do with even more scientific knowledge?
Explanation:
Scientific knowledge allows us to develop new technologies, solve practical problems, and make informed decisions, both individually and collectively.
Answer:
If we had more scientific knowledge, we would be able to increase the productivity of life-saving equipment that provides a longer life for us
be able to make more sensible and informed decisions
make more achievements in studies and be more accurate etc..
Hope this helps<3
_FeBr3 +_H2SO4 --->_Fe2(SO4)3 +_HBr
Answer:
2FeBr₃ + 3H₂SO₄ ⇒ Fe₂(SO₄)₃ + 6HBr
Explanation:
match the products and reactants of both sides.
Which of the diagrams below shows an atom that is not a form of hydrogen?
Answer:
I believe is the npp i kinda forgot how to do these lol
Diagram with npp type shows an atom that is not a form of hydrogen.
What is an atom?
An atom is defined as the smallest unit of matter which forms an element. Every form of matter whether solid,liquid , gas consists of atoms . Each atom has a nucleus which is composed of protons and neutrons and shells in which the electrons revolve.
The protons are positively charged and neutrons are neutral and hence the nucleus is positively charged. The electrons which revolve around the nucleus are negatively charged and hence the atom as a whole is neutral and stable due to presence of oppositely charged particles.
Atoms of the same element are similar as they have number of sub- atomic particles which on combination do not alter the chemical properties of the substances.
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HELP ASAP EILL MAKE BRAINLEST Students are conducting a la estimating the time takes for the cell cycle in normal chocols They find that the average time for one complete el cycle is 22 hours What arence would they expect to see nerous chien
Cancerous chicken cels will spend more time in the phase
Cancerous cells will not complete all phases of the cell cyce
Cancerus chin cells will complete moss in a shorter amount of time
O Cancerous chicken cols and normales will have the same total amount of time to complete the cell cycle
Answer: I don't know if this helps but here's some information I think might help.
Usually, cells will take between 5 and 6 hours to complete S phase. G2 is shorter, lasting only 3 to 4 hours in most cells. In sum, then, interphase generally takes between 18 and 20 hours. Mitosis, during which the cell makes preparations for and completes cell division only takes about 2 hours. Calculate the percentage of time spent in each phase by counting the total number of cells in each phase (total in interphase, in prophase, etc.) and dividing each by the total number of cells you counted. How do cancer cells differ in total time required for mitosis? Cancer cells produce 117 minutes faster than regular cells. ... Normal cells require 640 minutes during interphase, cancer cells only need 380. For prophase, cancerous cells need 15 minutes less than regular cells. Another hallmark of cancer cells is their "replicative immortality," a fancy term for the fact that they can divide many more times than a normal cell of the body. In general, human cells can go through only about 40-60 rounds of division before they lose the capacity to divide, "grow old," and eventually die 3.
How many grams of potassium nitrate are produced when 3.0 grams of
potassium phosphate reacts with excess grams of aluminum nitrate?
Answer 4.2 g. *
need answer ASAP
If 20.0g of water at 56.2°C absorbs 195 J of heat, what is the final temperature?
^in degrees celsius
What mass of water would increase in temperature from 45.0°C to 98.0°C after
absorbing 6830 J of energy?
^IN GRAMS
Answer:
1. 58.5°C = Final temperature
2. Mass of water = 30.8g
Explanation:
The general equation of specific heat of a substance is:
Q = C*m*ΔT
Where Q is the heat involved in Joules,
C is specific heat (Water = 4.184J/g°C),
m is mass of substance,
ΔT is change in temperature (Final temperature - Initial temperature)
For the first problem:
1. 195J = 4.184J/g°C*20.0g*ΔT
ΔT = 2.3°C = Final T - Initial T
ΔT = 2.3°C + 56.2°C =
58.5°C = Final temperatureIn the seconf problem:
2. 6830J = 4.184J/g°C*m*(98.0°C-45.0°C)
6830J / 4.184J/g°C*53°C = m
30.8g = m
Mass of water = 30.8gDiamonds are formed when carbon is placed under extreme heat and pressure. This process
in caves
in the ocean
In the atmosphere of Earth
beneath the surface of Earth,
Answer:
beneath the surface of Earth
Explanation:
Diamonds are made up of carbon that has been placed under extreme heat and pressure conditions.
These conditions of high pressure and temperature can only be found within the subsurface. As you go deeper to the mantle, the geothermal gradient rises significantly.
Also, the overburden pressure will also be high.
These processes can also occur on other planets and some can be associated to the earth times when the earth was being formed.
The condition at which diamond forms confers some of the distinct natural properties that typifies it.
The solids and liquids with the strongest intermolecular forces of attraction will have the
lowest melting and boiling points.
a. TRUE
b. FALSE
Please help
As the temperature increases, the molecular motion of the molecules decreases and it
becomes difficult to overcome the polar attractions.
a. TRUE
b. FALSE
What effects do winds patterns have on climate
Prevailing winds bring air from one type of climate to another. For example, warm winds that travel over water tend to collect moisture as they travel; the water vapor in the air will condense as it moves into colder climates, which is why temperate coastal areas often receive heavy rainfall.
Hope it Helps! T^T
how does the understanding of electron location allow us to change the world?
Answer:
The absorbed energy will change the electron's position. We can never know both the momentum and position of an electron in an atom.
Explanation:
Which statement describes a neutral atom?
A. positively charged, with the number of protons greater than the number of electrons B. negatively charged, with the number of electrons greater than the number of protons C. the number of protons equaling the number of electrons, with varying numbers of neutrons
D. the number of protons equaling the number of valence electrons only
Answer:
C
Explanation:
A neutral atom always has the same number of electrons and the total number of protons.
Lithium
Which statement about lithium describes what makes lithium very reactive?
F.
The number of neutrons in the nucleus.
G
The number of electrons in the first energy level.
H.
The number of protons in the nucleus.
J.
The number of electrons in the last energy level.
Answer:f
Explanation:
Which of the following best describes the relationship between the speed of sound and the type of medium?
A.
Sound travels slower in air because of the large distance between air particles
B.
Sound travels slower in solids because of the small distance between solid particles
C.
Sound travels slower in air because of the small distance between air particles
D.
Sound travels slower in solids because of the large distance between solid particles
Answer:
A. Sound travels slower in air because of the large distance between air particles
Explanation:
Sound is a mechanical wave that requires a medium for its propagation. Without a medium, sound cannot go through easily or readily. This implies that sound cannot be propagated through a vacuum.
A vacuum is an empty space without any particles in side. Sound waves travel fastest the most in solids because the particles are dense and close to one another. The speed of sound in air is the least because of the large distance between air particles. Therefore, the speed of sound is medium dependenthow many moles of oxygen molecules can be produced from 6 moles of lead oxide
Answer:
Moles of oxygen molecules produced = 3 mol
Explanation:
Given data:
Moles of oxygen molecules produced = ?
Number of moles of lead oxide decomposed = 6 mol
Solution:
Chemical equation:
2PbO₂ → 2PbO + O₂
Now we will compare the moles of oxygen and lead oxide.
PbO₂ : O₂
2 : 1
6 : 1/2×6 =3 mol
three moles of oxygen molecules are produced.
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Which wavelength would have the highest energy?
670 nanometers
1.3x10^-10 meters
5.3x10^-8 meters
1.5x10^-3 meters
Answer:
THE 3 third one
Explanation:
One gram of salt in swimming pool of water could be considered a _____ solution.
Answer:
Soluable
Explanation:
Because salt dissolves in water.. Your question has no background information to go off of
Answer:
dilute
Explanation:
trustt
How we can preserve the wetlands areas of nepal?
Answer:
Reduce, reuse, and recycle your waste and trash. Protecting the environment helps protect the wetlands, especially since trash can make its way into the water. The best and easiest way to protect the environment is by limiting your household waste.
How many electrons can fit in the sixth energy level
Answer:
72 electrons
Explanation:
The 6th shell could hold up to 2(6)² = 2(36) = 72 electrons
1. What processes change sediments into a sedimentary rock?
Which forms of energy are released by a burning candle? (2 points) a Light energy and chemical energy b Light energy and heat energy c Heat energy and electrical energy d Mechanical energy and heat energy
Answer:
light and chemical energy
Explanation: mark me brainliest please
I NEED HELP RN 40 POINTS
Answer:
B.) Adding a source of carbon dioxide to the water.
Explanation:
I had that question too.
How many grams of carbon are in 300 g of glucose
When a chemical change occurs:
A) the law of conservation of mass is always obeyed
B) the chemical properties of new substances are different from the ones you started with
C) all of the options are true
D) atoms are rearranged
Answer:
Are composed together
Explanation:
What is the density of a block with a volume of 5 cm3 and a mass of 20 g?
Answer: 4g/cm^3 or 4000g/L (4kg/L)
Explanation:
I'm not sure what units the question intended so I put both. For the first one, the equation for density is mass/volume so I divided the 20g by 5cm^3 to get 4g/cm^3. Just in case those aren't the intended units for volume and is instead liters, one cm^3 equals one ml. In addition, there are 1000ml in every liter so you can determine the amount per liter by multiplying 4g/ml by 1000 to get 4000g/L or 4kg/L.
I hope this helps.
Identify two reasons why the relative size of an atom become smaller due to the loss of electrons .
Answer:
nucleus as electrons are being added to the same principal energy level. These electrons are gradually pulled closer to the nucleus because of its increased positive charge. Since the force of attraction between nuclei and electrons increases, the size of the atoms decreases.
Explanation:
Nuclear attractive pull to the electrons results in smaller atomic radius. Two reasons that leads the size of an atom smaller by electron loss are nuclear pulling and emptying outermost orbital.
Why atomic radius reduces by electron loss?
The nucleus have a net positive charge and electrons are negative in charge, thus, each electron experience a nuclear attractive pull. However, each electrons are shielded slightly from this attraction by the surrounding electrons.
The reasons which make the atomic radius smaller are the following.
By losing electrons the total number of electron is reducing therefore, the screening or shielding of an electron by other electron from the nuclear attractive pulling reduces, and thus due to the nuclear attraction, the orbitals shrinks inwards and reduces the atomic size. By losing electron from the outermost orbital if it contains only one electron then the orbital becomes empty and the atomic radius shrinks to the penultimate shell or orbital.
Therefore, due the two reasons mentioned above, the atomic radius reduces by electron loss.
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