Answer: 541 million to 485.4 million years ago
Explanation:
Which compound has a covalent bond?
H2O
Li2O
Na2O
K2O
Answer:
The correct answer is H20
Explanation:
A. is the correct answer!
The half-life of Radon-222 is 3.8 days. If a 10 gram sample is present, how many days will it take to have less than one gram remaining?
(alt + F4) might be the answer you are looking
Explanation:
I'm not exactly sure how I came up with this answer but it is for sure the answer
Where within the cell does the process of respiration take place?
Answer:
cytoplasm
Explanation:
Answer:
mitochondria
Explanation:
While most aerobic respiration (with oxygen) takes place in the cell's mitochondria, and anaerobic respiration (without oxygen) takes place within the cell's cytoplasm
Is it ture the sun moves across the sky
Answer:
Yes, this statement is true. The sun moves across our sky from east to west.
Explanation:
(fun fact: on Mars the sun moves across the sky from west to east!)
Which statement correctly describes how energy transforms?
When a fire is burning, chemical energy is turned into visible energy in the form of light and thermal energy in the form of heat.
When a fire is burning, visible energy is turned into thermal energy in the form of light and chemical energy in the form of heat.
When a fire is burning, thermal energy is turned into visible energy in the form of light and chemical energy in the form of heat.
When a fire is burning, visible energy is turned into chemical energy in the form of light and thermal energy in the form of heat.
Answer: When a fire is burning, chemical energy is turned into visible energy in the form of light and thermal energy in the form of heat.
Explanation:
An example of a chemical change is
A dew disappearing from the grass
B mashing potatoes
C a magnet sticking to the refrigerator
D frying a hamburger
Answer:
D.) Frying a hamburger
Explanation:
A, B, and C are all physical changes whereas D is a change that alters its chemical makeup.
1. What objects in this picture are in motion?
2.What is the unbalanced force in this picture?
3. What happened to the sledder in this picture?
Sled is the object in this picture which is in motion. Sled hitting rock is the unbalanced force in this picture. He took off when they were startled by the abrupt stop.
What is force?A force is an external cause that, when applied, alters or has the potential to alter a body's condition. The body comes to rest while it is moving, and it moves when it is at rest. The body's orientation, form, size, etc. may also alter as a result. An illustration would be to push or forcefully shove a door. Force has both a magnitude and a direction since it is a vector quantity.
Sled is the object in this picture which is in motion
Sled hitting rock is is the unbalanced force in this picture
He took off when they were startled by the abrupt stop
Therefore, Sled is the object in this picture which is in motion. Sled hitting rock is is the unbalanced force in this picture. He took off when they were startled by the abrupt stop.
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Which phrase describes chemical potential energy?
A) the amount of energy stored in bonds
B) the amount of energy absorbed by products
C) the amount of energy needed to break a bond
D) the amount of energy absorbed by reactants
Answer:
the amount of energy stored in bonds
Explanation:
potential energy is stored energy and chemical just refers to energy stored in chemical bonds
i took the quiz
The term describes chemical potential energy is the amount of energy stored in chemical bonds. Hence, option C is correct.
What is chemical potential energy ?Chemical potential energy is the energy held inside a substance's chemical bonds. When gasoline is burnt in a regulated manner in the car's engine, a significant quantity of chemical potential energy that is present in the many compounds that make up gasoline is released.
When that energy is released, two things happen: part of the potential energy is converted into work, which is used to drive the automobile, and some of it is also converted to heat, which heats up the engine of the car. A system's energy changes take the form of heat, work, or a mix of the two.
Therefore, option A is correct.
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In eukaryotic cells, mRNA is produced in the....
A. cell membrane
B. endoplasmic reticulum
C. Golgi body
D. nucleus
A Teacher had her students write down hypothesis about an experiment. Which is a valid hypothesis? (1 point)
Answer:
You need to add the options to this question.
Explanation:
Anyone know any good chemistry jokes???
Answer:
What do you do with a sick chemist? If you can't helium, and you can't curium, then you might as well barium!
Explanation:
there
Answer:
why can you never trust a atom?
Because they literally make up everything
(i am so sorry for this lol)
Convert 5.38 kPa to torr
What is the mass in grams of 10 moles of ammonia, NH3?
Answer:170 grams
explanation: :)
I need help with this question, I don't get it!
Answer:Its c
Explanation:
Let us use a double displacement reaction of Lead (II) Nitrate and Potassium Chromate to produce Lead (II) Chromate and Potassium Nitrate to practice balancing an equation.
We begin with the base equation provided in the question.Pb(NO3)2(aq)+K2CrO4(aq)→PbCrO4(s)+KNO3(aq)
Looking at the the atom inventory ReactantsPb=1NO3=2
K=2CrO4=1
Products
Pb=1
NO3=1
K=1
CrO4=1
We can see that the
Kand NO3
are imbalanced.
If we add a coefficient of 2 in front of the
KNO3
this will balance the equation.
Pb(NO3)2(aq)+K2CrO4(aq)→PbCrO4(s)+2KNO3(aq)
The equation for the pH of a substance is pH = –log[H ], where H is the concentration of hydrogen ions. What is the approximate pH of a solution if the concentration of hydrogen ions is 5. 0 × 10–4 moles per liter? 2. 7 3. 0 3. 3 3. 6.
The formula is pH = -log[[tex]H^{+}[/tex]]. You are given the concentration of hydrogen ions so all you need to do is input that into the formula.
[tex]pH=-log[H^{+}]\\\\pH=-log[5.0x10^{-4}]\\\\pH=3.30[/tex]
what is the mole ratio of SnF2 to HF
Answer:
Answer:
12. 5
11.
10
10
15. 7
14. 11
2
=
16
16
18. 3
+
11
17
3
4
co
loo
8
Step-by-step explanation:
12. 5
11.
10
10
15. 7
14. 11
what is mommentum machnics
Answer:
momentum, product of the mass of a particle and its velocity. Momentum is a vector quantity; i.e., it has both magnitude and direction. Isaac Newton's second law of motion states that the time rate of change of momentum is equal to the force acting on the particle. See Newton's laws of motion.
How many molecules are in 34.61 grams of sulfur dioxide?
Give your answer in scientific notation using the form M*10^N
Type your answer...
This problem is providing us with the mass of sulfur dioxide and the molecules contained are required. At the end, the result turns out to be 3.252x10²³ molecules, according to:
Avogadro's number:In chemistry, we use the Avogadro's number in order to successfully perform mole-mass-particles calculations. Defined as 6.022x10²³, it provides the number of atoms, molecules and ions in one mole of the substance.
In this case, in order to obtain the result, one first calculates the moles in 34.61 grams of sulfur dioxide and then utilize the Avogadro's number to obtain the number of molecules as shown below:
[tex]34.61gSO_2*\frac{1molSO_2}{64.1gSO_2}*\frac{6.022x10^{23}molecules}{1molSO_2} \\\\3.252x10^{23}molecules[/tex]
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Humans belong to the Kingdom Animalia and Domain Eukarya. In terms of classification, which choice best represents the hierarchy of kingdoms and domains relative to each other?
A) Kingdoms are larger than domains and include more organisms.
B) Domains are larger than kingdoms and include more organisms.
C) Kingdoms are larger than domains and include fewer organisms.
D) Domains are smaller than kingdoms and include more organisms.
Domains are larger than kingdoms and include more organisms as far as the classification of living organisms is concerned.
Domains
When it comes to classifying living organisms, the highest level of classification is the domain. Under each domain is where we have the kingdoms.
For example, the domain eukarya contain four kingdoms; plant, animal, fungi, and protozoa.
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Answer:
The Answer is B
Explanation:
Domains are larger than kingdoms :) Your welcome
true or false a neutral atom must have the same number of neutrons and protons
do isomers have the same chemical and physical properties? State a reason for your answer
Answer:
your answer is
isomerism, the existence of molecules that have the same numbers of the same kinds of atoms (and hence the same formula) but differ in chemical and physical properties.
Hope it’s helps you Buddy
Explanation:
~Zayn
A chemist obtains a sample of
sodium sulfate, Na2SO4, with a mass of 71.0 g. How many formula units of sodium sulfate are in the sample?
The number of formula units of Na₂SO₄ present in the sample is 3.01×10²³ units
Avogadro's hypothesisFrom Avogadro's hypothesis,
1 mole of Na₂SO₄ = 6.02×10²³ units
But
1 mole of Na₂SO₄ = (23×2) + 32 + (16×4) = 142 g
Thus,
142 g of Na₂SO₄ = 6.02×10²³ units
How to determine the units in 71 g of sample142 g of Na₂SO₄ = 6.02×10²³ units
Therefore,
71 g of Na₂SO₄ = (71 × 6.02×10²³) / 142
71 g of Na₂SO₄ = 3.01×10²³ units
Thus, 3.01×10²³ units of Na₂SO₄ is present in the sample
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the volume of a cylindrical tin can with a top and a bottom is to be 16Ï cubic inches. if a minimum amount of tin is to be used to construct the can, what must be the height, in inches, of the can
Answer:
The required height of the tin can is given by the height at the minimum value of the surface area function of the tin can
The height of the tin can must be 4 inches
Reason:
The given information on the tin can are;
Volume of the tin can = 16·π in.³
The amount of tin to be used = Minimum amount
The height of the can in inches required
Solution;
Let h, represent the height of the can, we have;
The surface area of the can, S.A. = 2·π·r² + 2·π·r·h
The volume of the can, V = π·r²·h
Where;
r = The radius of the tin can
h = The height of the tin can
Which gives;
16·π = π·r²·h
16 = r²·h
Which gives;
When the minimum amount of tin is used, we have;
Therefore;
4·π·(r³ - 8) = r² × 0
r³ = 8
r = 2
The radius of the tin can, r = 2 inches
The
The height of the tin can, h = 4 inches
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Explanation:
What’s the empirical formula of a molecule containing 65.5% carbon, 3.5% hydrogen, and 32.0% oxygen?
Answer:
attached
Explanation:
answer attached
hope this helps!
Help please!
Read the scenario and decide whether the observations are qualitative and/or quantitative.
Danielle and Heather were in science class when they volunteered to fill the fish tank in the back of the room using a long hose connected to the sink. Mr. Ferris told them to fill the tank almost to the top and to be sure not to overflow the tank. The girls wanted to know how much water the tank could hold, so they recorded the length, width and height of the tank in centimeters. Next, they determined the total volume of the tank using the formula, length x width x height.
The observation, in this case, is quantitative.
Quantitative observationQuantitative observations are observations that can be recorded based on quantitative data. In other words, they are observations that can be assigned numerical values.
Quantitative observations are as opposed to qualitative observations because the former cannot be assigned numerical values. They can be ranked or qualified.
In this case, Danielle and Heather could assign numbers to the length, width, and height of the tank in order to calculate its volume.
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A researcher can determine that an exothermic reaction has occurred in a flask if …
A) the flask feels cool.
B) minimal particle movement is visible.
C) lots of particle movement is visible.
D) the flask feels warm.
Answer:
the flask feels warm
Explanation:
in exothermic reaction heat is leaving the system and entering the surroundings aka the flask
also i took the quiz
What is the empirical formula for a compound that is 24.7 % calcium, 1.20 % hydrogen, 14.8 % carbon, and 59.3 % oxygen? *
Answer:
[tex] C_2H_2O_6Ca [/tex]
Explanation:
Here we are given that the percentage of ,
Calcium = 24.7% Hydrogen = 1.20%Carbon = 14.8% Oxygen = 59.3%And we need to find out the Empirical formula of the compound .
Firstly divide the given percentage by the atomic mass of the compound . Here this is followed in the fourth column of the table , which will give the relative number of atoms .Secondly , divide the value obtained by the smallest value among them .Say if we got the relative number of atoms as 4 , 3 and 2 , then divide all three numbers by 2 . ( followed in 5th column below .)Finally write the Empirical formula of the compound by writing the ratio obtained as the subscript of respective compounds .Let's make a table ,
[tex]\boxed{\begin{array}{c|c|c|c|c} \underline{\bf Element} & \underline{\bf Percentage} & \underline{\bf Atomic \ Weight } &\underline{\bf No. \ of \ atoms_{relative} } &\underline{\bf Ratio } \\\\ \sf Ca & \sf 24.7 &\sf 40 &\sf \dfrac{24.7}{40}=0.6 &\sf \dfrac{0.6}{0.6}=1 \\\\\sf H &\sf 1.20 &\sf 1 &\sf \dfrac{1.20}{1}=1.20&\sf \dfrac{1.20}{0.6}=2\\\\\sf C &\sf 14.8 &\sf 12&\sf\dfrac{14.8}{12}=1.23&\sf \dfrac{1.23}{0.6}=2\\\\\sf O &\sf 59.3 &\sf 16 &\sf\dfrac{59.3}{16}=3.7&\sf \dfrac{3.7}{0.6}=6 \end{array}}[/tex]
Therefore we got the ratio of Ca , H , C and O as 1:2:2:6 . Therefore the Empirical formula of the compund will be ,
[tex]\longrightarrow\underline{\boxed{\bf Empirical \ formula = C_3H_2O_6 Ca }}[/tex]
The empirical formula of the compound is written as C₂H₂O₆Ca.
What is empirical formula?
The empirical formula of a compound is the simplest structural formula of the compound.
Fraction of the elements in the given compound;
Ca, = 24.7/40 = 0.62
H, = 1.2/1 = 1.2
C, = 14.8/12 = 1.23
O, = 59.3/16 = 3.7
Ca: = 0.62/0.62 = 1
H: = 1.2/0.62 = 2
C: = 1.23/0.62 = 2
O: = 3.7/0.62 = 6
Thus, the empirical formula of the compound is written as C₂H₂O₆Ca.
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Identify the single displacement reaction. 2H 2 O 2 ⟶ 2H 2O Al 2S 3 ⟶ 2Al 3S Cl 2 2KBr ⟶ 2KCl Br 2 C 4H 12 7O 2 ⟶ 6H 2O 4CO 2.
Reaction three is the single replacement reaction.
A single displacement or replacement reactions are the exchange of a single element with another compound or element.
Which is the single-displacement reaction?The first reaction is a combination reaction as the water and oxygen combines togetherly to produce hydrogen peroxide and hence is incorrect.
The second reaction is a decomposition reaction in which the reactant [tex]\rm Al_{2}S_{3}[/tex] breaks into two products [tex]\rm 2Al[/tex] and [tex]3\rm S[/tex].
The third reaction is the single replacement reaction as more reactive [tex]\rm Cl_{2}[/tex] displaces [tex]\rm Br[/tex] from the potassium to produce [tex]\rm 2KCl[/tex] and [tex]\rm Br_{2}[/tex].
The fourth reaction is a combustion reaction as hydrocarbon reacts with the oxygen molecule to produce water and carbon dioxide.
Therefore, [tex]\rm Al_{2}S_{3} \rightarrow2Al + 3S[/tex] is the single-displacement reaction.
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In this food chain, which describes all of the
possible energy sources for the bacteria?
Answer:
Energy flows from primary producers to consumers, in one direction only
Explanation:
What can you conclude about the reactivity of metals as you move down a column or group in the periodic table.
Answer:
Reactivity increases down the group
Explanation:
This is because metals reaction involves loss of an electron from an occupied orbital.
As we go down the group the relative nuclear charge decreases due to an additional orbit leading to ease in loss of an electron
Due to ease in loss of electrons down the group metals become more reactive down the group
