the answer is B) All cells come from existing cells
The point which is not a part of the cell theory is your brain is constantly making new cells.
What is cell theory?Cell theory is a scientific theory and in this theory following three basic points are mentioned:
Cells are the basic and fundamental unit of all living life.New cells are formed from the cells which are already present.All living organisms are composed of cells.So, your brain is constantly making new cells is not the part of cell theory.
To know more about cell theory, visit the below link:
https://brainly.com/question/24595992
What is the difference between an element and a compound? Give an example of each.
please answer in a sentence.
Answer:
An element is a single atom by itself found on the periodic table. A compound is made when two or more elements chemically bond together. An example of an element is hydrogen. (H) An example of a compound is [tex]H_{2} O[/tex].
Explanation:
explained above
What is a mole in chemistry
Answer:Mole, also spelled mol, in chemistry, a standard scientific unit for measuring large quantities of very small entities such as atoms, molecules, or other specified particles.
Explanation:
How many mL are in 7.3 dL?
Answer:
730 mL which is .73 L
Explanation:
The mass spectrum of the element Sb is most likely represented by which of the following?
A. 122 Atomic Mass
B. 121 and 123 Atomic Mass
C. 120, 123 and 124 Atomic Mass
D. 120,121 and 124 Atomic Mass
i know the answer is b i just need an explanation
Mass spectrometry is the technique that measures the ratio of mass to charge. The spectrum of the element Sb is most likely represented by 121 and 123 atomic mass. Thus, option B is correct.
What is Mass spectrometry?Mass spectrometry plots the spectrum representing the ratio of mass-to-charge by the signals generated by the ions. The spectrum estimates the mass and isotopes of the sample elements. They also determine the chemical properties and structures.
The spectrometry detects the isotopes that are stable and are known to have the same atomic number. It can be used to determine the isotopes of an element based on their peaks generated on the mass spectrum. Antimony has two stable isotopes with atomic masses 121 and 123.
Therefore, option B. the spectrum of the element Sb is most likely represented by Sb-121 and Sb-123.
Learn more about mass spectrometry here:
https://brainly.com/question/27549121
#SPJ6
identify the PowerHouse of a cell
A. Golgi
B. lysosome
C. ribosomes
D. nucleus
E. mitochondrion
F. cytoplasm
G. rough endoplasmic reticulun
H. membrane
Sara takes a 40-minute bus ride from her home to her grandparents’ home, which is 8 km away. What is the average speed of the bus.
12 Km / hour
Explanation:
using the formula
average speed = ( where time is in hours )
40 min = = hour
speed = 8 ÷ = 8 × = 12 Km / hour
Answer:
12 Km / hour
Substances exist as a solid, a liquid, or a gas because…
Which thing has the greatest
mass and volume?
• a very large rock
• a big balloon
• a mud puddle
• a car
Answer:
either a car or a rock
Explanation:
because the rock can weigh more than the car , and vice-versa with the car weighing more than the rock
Which statement best describes the atoms of the gas neon?
They slide past each other.
They move freely in all directions.
They vibrate in place.
They are packed closely together.
Answer:
B. They move freely in all directions.
Explanation:
i got it right on my test on edge
Answer:
B. They move freely in all directions.
Explanation:
Please Help !! Brainliest !!
Which property refers to how light reflects off of a mineral?
A. fracture
B. cleavage
C. streak
D. luster
Answer:
D. Luster
Explanation:
Luster describes how a mineral reflects off light. It is in the definition.
When paper is burned, the mass of the remaining ash is less than the mass of the original paper.
Which statement best explains this result?
0 The ash has less volume than the paper.
O Some of the matter is destroyed during the reaction.
O The mass of the ash cannot be accurately determined.
O Some of the products of the reaction were given off as a gas.
When paper is burned, the mass of the remaining ash is less than the mass of the original paper because Some of the products of the reaction were given off as a gas.
The postulate of the law of conservation of mass is that mass can not be created or destroyed rather it can be transformed from one form to another.
This means that when ash is left behind after burning paper, the total mass should be the same as was obtained before combustion but it rather weighs less than paper itself. This should never be interpreted to mean that mass was "lost".
Here is what happens, paper is an organic material and burning it in air yields CO2 gas which escapes into the atmosphere. This explains why; when paper is burned, the mass of the remaining ash is less than the mass of the original paper.
Learn more: https://brainly.com/question/13048470
The half-life of Th-227 is 18.2 day. How many days are required for 0.70g of a given sample
to decay to 0.04375 g?
Answer:
73 days
Explanation:
From the question given above, the following data were obtained:
Half life (t½) = 18.2 day.
Original amount (N₀) = 0.70 g
Amount remaining (N) = 0.04375 g
Time (t) =.?
Next, we shall determine the rate of decay of the isotope. This can be obtained as follow:
Half life (t½) = 18.2 day.
Decay constant (K) =.?
K = 0.693 / t½
K = 0.693 / 18.2
K = 0.038 /day
Finally, we shall determine the time taken for the isotope to decay to 0.04375 g. This can be obtained as follow:
Original amount (N₀) = 0.70 g
Amount remaining (N) = 0.04375 g
Decay constant (K) = 0.038 /day
Time (t) =.?
Log(N₀/N) = kt /2.303
Log (0.70/0.04375) = (0.038 × t) /2.303
Log 16 = (0.038 × t) /2.303
1.2041 = (0.038 × t) /2.303
Cross multiply
1.2041 × 2.303 = 0.038 × t
Divide both side 0.038
t = (1.2041 × 2.303) / 0.038
t = 72.97 ≈ 73 days
Therefore, it will take approximately 73 days for the isotope to decay to 0.04375 g
Lactic acid, C3H6O3, is a monoprotic acid that is available in solid form. Determine the concentration of an unknown solution of sodium hydroxide, in moles per litre, given that it takes 18.34 mL to neutralize a solution containing 0.821 g of lactic acid. Write a balanced chemical equation for the reaction .
Answer:
0.497 moles/L
Explanation:
The reaction that takes place is:
C₃H₆O₃ + NaOH → C₃H₅ONa + H₂OFirst we calculate the moles of lactic acid in 0,821 g, using its molar mass:
0,821 g ÷ 90 g/mol = 9,122x10⁻³mol lactic acidOne mole of lactic acid reacts with one mole of sodium hydroxide (it is a monoprotic acid), so in 18,34 mL of NaOH solution there are 9,122x10⁻³moles of NaOH:
18.34 mL ÷ 1000 = 0,01834 L 9,122x10⁻³mol ÷ 0,01834 L = 0.497 moles/LNatural process in which certain gases in the atmosphere keep heat near earth and prevent it from radiating into to space
The greenhouse effect is a process in which gases in the atmosphere keep heat near earth and prevent it from radiating into space.
What is the greenhouse effect?Greenhouse effect can be described as the process by which radiations from the sun are absorbed by greenhouse gases and do not travel back into space. This prevents the surface of the earth from freezing.
The sun heats up the earth’s atmosphere during the day and the earth cools down at night by radiating heat back into the atmosphere. The heat is absorbed by the greenhouse gases and makes the surface of the earth warmer, which makes the survival of living beings on earth possible.
But because of the increased levels of greenhouse gases, the temperature of the earth has considerably increased. The major contributors to greenhouse gases are automobiles, deforestation, factories, etc. which increases the amount of these gases in the atmosphere.
The greenhouse gases do not allow radiation or heat to escape from the earth and increasing the surface temperature of the earth and leading to global warming.
Learn more about the Greenhouse effect, here:
https://brainly.com/question/13390232
#SPJ6
find the density of a brick that has a mass of 57 g and a volume of 12 ml
Answer:
4.75 or 4.8
Explanation:
density = mass / volume
57 / 12 = 4.75
from here you can leave it as is or round up.
hope this helps!!
1. Which of the following substances are elements?
(a) bronze
(b) tin
(c) chromium
(d) solder
(e) propane
(1) arsenic
(g) nickel
Which descriptions apply to eukaryotic cells? Check all that apply.
are usually multicellular
contain a true nucleus
contain membrane-bound organelles
has DNA located in the cytoplasm
Answer:
The first 3
Explanation:
Eukaryotic cells are usually multicellular, contain a true nucleus, and contain membrane-bound organelles. Hence, options A, B and C are correct.
What are Eukaryotic cells?The eukaryotic cell has a nuclear membrane that surrounds the nucleus, in which the well-defined chromosomes (bodies containing the hereditary material) are located.
Eukaryotic cells are usually multicellular, contain a true nucleus, and contain membrane-bound organelles.
Hence, options A, B and C are correct.
Learn more about Eukaryotic cells here:
https://brainly.com/question/725029
#SPJ2
Which expression represents the number 0.00017 written in scientific notation?
A.1.7 x 10-3
B.1.7 x 103
C.1.7 x 104
D. 1.7 x 10-4
Answer:
D
Explanation:
Move the decimal and count the places
Answer dis please I will like and 5 star if correct
How many kg is 59.0 mg?
Answer:
5.9e-5
Explanation:
Periodic Trends
PLEASE HELP ME! I WILL GIVE BRAINLIEST
Please help brainiest is award!!!!!!!!!!!
Answer:
it doesnt even give you enough information for you to answer it
Explanation:
Answer:
it doesnt even give you enough information for you to answer it
Explanation:
Define physical change
Answer to Question.
A physical change is a change to the physical—as opposed to chemical—properties of a substance. They are usually reversible. The physical properties of a substance include such characteristics as shape (volume and size), color, texture, flexibility, density, and mass.
What elements are involved with fission
Answer:
Several heavy elements, such as uranium, thorium, and plutonium, undergo both spontaneous fission, a form of radioactive decay and induced fission, a form of nuclear reaction.
Which process is a chemical change?
burning a match
boiling water
melting ice
breaking glass
Answer:
the answer is burning a match
Explanation:
when you break glass, the properties of glass is still the same, melting ice and boiling water are both phyisical changes since they are chnages in state.
woo burning is a type of combustion reaction and when we light a match, matches include different chemicals that help to ignite it with friction so its A, burning a match
Answer:
A. burning a match on edge 2021
PLEASE HELP ASAP ONLY HAVE 10 MINUTES. A certain photon of light has a wavelength of 422 x 10 -9 m. What is the frequency of the light? Show work
Answer:
7.11 x [tex]10^{14}[/tex] Hz
Explanation:
The equation for converting wavelength to frequency is ν=c/λ, or the speed of light over wavelength. The speed of light is 3.00 x [tex]10^{8}[/tex], and our wavelength here is 422 x [tex]10^{-9}[/tex]. All we have to do now is substitute our given values:
[tex]\frac{3.00x10^{8} }{422x10^{-9}}[/tex]
After reduction, our answer comes out to be about 7.11 x [tex]10^{14}[/tex] Hz.
How are covalent molecules named?
A. A number is used in front of each element's name, and the first element is changed to end in -ide.
B. A prefix is added to each element's name, and the second element is changed to end in -ide.
C. A roman numeral is used to indicate the number of atoms of each element.
D. The name of each element is followed by a number to indicate the amount of atoms.
Answer:
A prefix
Explanation:
you're welcome
The covalent molecules named as,
A prefix is added to each element's name, and the second element is changed to end in -ideSo, option B is correct one.
What is covalent molecules?The molecule formed by sharing of electrons between atoms is called covalent molecules .The atoms which form covalent molecules must have similar or less electnegativity difference.Examples of covalent molecules are hydrogen molecule [tex]H_{2}[/tex] ,carbon dioxide, methane etcTo learn more about covalent molecules,
https://brainly.com/question/1646189
#SPJ2
What does electro negativity value depend on ?
Answer:
An atom's electronegativity is affected by both its atomic number and the distance at which its valence electrons reside from the charged nucleus. The higher the associated electronegativity, the more an atom or a substituent group attracts electrons.
Explanation:
Hope this helps :)
The half life of iodine-125 is 60 days. What was the initial amount of iodine-125 if you have 4.5 grams after 360 days?
Answer:
288 grams
Explanation:
The amount of any radiative substance left after some time is calculated by
amount left = [tex]x/2^n[/tex]
where x is the initial amount of substance
n is the number of half lives
one half live is the time in which amount of substance reduce to half of its initial value.
------------------------------------------------------
amount left = 4.5 grams
half life of iodine-125 = 60 days
total time in which substance reduced to 4.5 grams = 360 days
thus,
number of half life in 60 days = 360/60 = 6
thus, there are period of 6 half lives
in each half life the amount of substance reduces to its previous half
let the initial amount be x grams
using the formula
amount left = [tex]x/2^n[/tex]
[tex]4.5 = x/2^6 \\ 4.5 = x/64\\x = 4.5*64 = 288[/tex]
Thus, 288 grams was the initial amount of iodine-125
