What happens when molecules diffuse across the cell membrane?
Answer:
The correct answer is from areas of high concentration to low concentration.
Explanation:
A concentration gradient exists for these molecules, so they have the potential to diffuse into (or out of) the cell by moving down it.
Hope this Helps!
The sum of the protons and neutrons in an atom equals the?
nucleus number
atomic number
atomic mass
mass number
Answer:
mass number
Explanation:
The sum of the protons and neutrons in an atom equals the mass number of such an atom.
Mass number is the mass of an atom. The mass of an atom is concentrated in the nucleusThe particles in the nucleus are the protons and neutrons.So;
Mass number = number of protons + number of neutrons.
Part of a chemical equation is shown below 2koh + h2so4 .
Wich pair of chemicals most likely comes after the arrow to complete the equation.
Answer: K2SO4 + 2H2O
Explanation:
I got it right
Answer:
K2SO4 + 2H2O
Explanation:
which of these changes could be classified as producing a chemical changes
Answer:
hhhhhhhh
Explanation:
OTTTTTTTTTTTTTTTT
Question 14
1 pts
How many moles of NaCl could be found in 0.4 L of a 0.9 M solution? Round your answer to
two decimal places.
Answer:
0.36mol
Explanation:
Given parameters:
Volume of NaCl = 0.4L
Molarity = 0.9M
Unknown:
Number of moles = ?
Solution:
To find the number of moles, the molarity of a solution is the amount of solute contained in a solution.
Molarity = [tex]\frac{number of moles}{volume}[/tex]
Number of moles = molarity x volume
Insert the parameters and solve;
Number of moles = 0.4 x 0.9 = 0.36mol
What is an important part of the endocrine system that acts as a chemical messenger?
hormones
arteries
spinal cord
neurons
consider the following reaction: Mg(s)+2HCl(aq)--->MgCl2(aq)+H2(g) the total pressure of gas collected over water is 650.0 mmhg and the temperature is 19.0 c. what is the pressure of hydrogen gas formed in mmHg
Answer:
633.5
Explanation:
The total presser is 650.00 mmHg, and it is collected over water, which at 19c is 16.5 mmHg. Therefore, to get the total pressure of H2 you would subtract the partial pressure of water from the total pressure.
650-16.5=633.5
633.5 mmHg is the pressure of hydrogen gas formed in mmHg.
According to the Dalton's law of partial pressure, the total pressure of a gas mixture is the sum of all the partial pressure of the individual gases present in the mixture of gases.
Hence;
Total pressure = pressure of hydrogen gas + vapour pressure of water
pressure of hydrogen gas = Total pressure - vapour pressure of water
vapour pressure of water at 19°C = 16.5 mmHg
pressure of hydrogen gas = 650.0 mmHg - 16.5 mmHg
pressure hydrogen of gas = 633.5 mmHg
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Which of the following is a true difference between protons and neutrons?
a
the have different masses
b
they are in different locations in the atom
c
the proton identifies the atom and the neutrons does not
d
all of the choices are true
Answer:
D
Explanation:
Which three statements about forces are true?
A. Some forces cause objects around us to move,
B. Force can cause changes in the motion and energy of matter,
C. Every force can be identified as one of the fundamental forces,
D. Force is the ability to change motion and transfer matter,
E. Some forces keep objects around us from moving,
Answer:
A. Some forces cause objects around us to move,
C. Every force can be identified as one of the fundamental forces,
D. Force is the ability to change motion and transfer matter,
Explanation:
Force basically is defined as pull or push on a body. Forces are known to cause the change in motion of a body as the amount of force applied is attenuated.
Every known force in the universe can be traced to the four fundamental forces which are gravitational force, electromagnetic, strong and weak forces. Force enables a body to change its motions by acceleration.What properties do all basses have?
According to the periodic table, the neutral atom of what element has 4
protons, 5 neutrons, and 4 electrons?
Answer:
Beryllium
Explanation:
Given parameters:
Number of protons = 4
Number of neutrons = 5
Number of electrons = 4
Unknown:
Element = ?
Solution:
To determine an element, the atomic number is the most important identifier.
The atomic number is the number of protons in an atom.
Since the atom here has a proton number of 4, checking on the periodic table, it is Beryllium, Be
an object has a mass of 55 grams and a density of 3.23g/ml ? what is the volume
FePO4 + Na2SO4 Fe2(SO4)3 + Na3PO4
If you perform this reaction with 24 grams of FePO4 and an excess Na2SO4, how many grams of Fe2(SO4)3 can you make?
Mass Fe₂(SO₄)₃ : 31.79 g
Further explanationReaction
2FePO₄ + 3Na₂SO₄ ⇒ Fe₂(SO₄)₃ + 2Na₃PO₄
mol FePO₄ (MW=150,82 g/mol) :
[tex]\tt \dfrac{24}{150.82}=0.159[/tex]
mol Fe₂(SO₄)₃ : mol FePO₄ = 1 : 2, so mol Fe₂(SO₄)₃ :
[tex]\tt \dfrac{1}{2}\times 0.159=0.0795[/tex]
mass Fe₂(SO₄)₃ (MW=399,88 g/mol) :
[tex]\tt 0.0795\times 399,88 g/mol=31.79~g[/tex]
An aquifer receives 40 m3 of precipitation and loses 10 m3 of water through natural movement. How much water can be pumped from the aquifer to balance the budget? 10 m3 20 m3 30 m3 40 m3
Answer:
30m3
Explanation:
<3
The amount of water that can be pumped from the aquifer to balance the budget is 30 m³.
Material BalanceThe principles of material balance states that, the total mass of an isolated system is always conserved.
Mass (in) = Mass (out)
Water pumped from the aquiferThe water pumped from the aquifer can be determined by applying the principle of material balance.
10 + m = 40
m = 40 - 10
m = 30 m³
Thus, the amount of water that can be pumped from the aquifer to balance the budget is 30 m³.
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help asap
i have to get a good grade on this
50 chemical equations
Answer:Hey there
Here are 50 simple balanced chemical equations...
1) 2Fe2O3+3C--->4Fe+3CO2
2)H2SO4+
CaCO3--->CaSO4+H2CO3
3) 2H2+02--->2H20
4) CH3COOH+
C2H5OH ---> CH3COOC2H5
+H2O
5) 1 AgNO3 + 1 LiOH --> 1 AgOH + 1 LiNO3
6) CH4+2O2--->CO2+2H2O.
7) Sn+2H2SO4-->SnSO4+2H2O
+SO2
8) CuO+H2SO4--->CuSO4+H2
9) Mg3N2 + 3H2O ---> 3MgO + 2NH3
10) N2 + O2 ---> 2 NO
11) 2 CH4 + 3 O2 ---> 2 CO + 4 H2O
12) 6 CO2 + 6 H2O ---> C6H12O6 + 6 O2
13) 2 AgI + Na2S ---> Ag2S + 2 NaI
14) Ba3N2 + 6 H2O --->
3 Ba(OH)2 + 2 NH3
15) 4 FeS + 7 O2 --->2 Fe2O3 + 4 SO2
16) PCl5 + 4 H2O ---> H3PO4 + 5 HCl
17) 3 CaCl2 + 2 Na3PO4--->Ca3
(PO4)2 + 6 NaCl
18) 2 As + 6 NaOH --->2 Na3AsO3 + 3 H2
19) 12 HClO4 + P4O10 ---> 4 H3PO4 + 6 Cl2O7
20) 10 KClO3 + 3 P4 ---> 3 P4O10 + 10 KCl
21) SnO2 + 2 H2 ---> Sn + 2 H2O
22) 3 KOH + H3PO4 ---> K3PO4 + 3 H2O
23) 3 Hg(OH)2 + 2 H3PO4 ---> Hg3(PO4)2 + 6 H2O
24) 2 KNO3 + H2CO3 ---> K2CO3 + 2 HNO3
25) Na3PO4 + 3 HCl ---> 3 NaCl + H3PO4
26) TiCl4 + 2 H2O ---> TiO2 + 4 HCl
27) C2H6O + 3 O2 ---> 2 CO2 + 3 H2O
28 4 NH3 + 5 O2 ---> 4 NO + 6 H2O
29) B2Br6 + 6 HNO3 ---> 2 B(NO3)3 + 6 HBr
30) 8 CO + 17 H2 ---> C8H18 + 8 H2O
31) 4 NH4OH + KAl(SO4)2·12H2O ---> Al(OH)3 + 2 (NH4)2SO4 + KOH + 12 H2O
32) 2 Fe + 6 HC2H3O2 ---> 2 Fe(C2H3O2)3 + 3 H2
33) N2+3H2--->2NH3
34) N2 + 3H2 ---> 2NH3
35) Al2O3+3H2SO4--->Al2
(SO4)3 +3H2O
36) HCl+NH3--->NH4Cl
37) 2Na + 2H2O = 2NaOH + H2
38) C6H12O6--->6C+6H2O
39) CuO+H2SO4--->CuSO4+H2
40) COH12O6--->2CO2
+2C2H5OH
41) FeCl3+Fe2O3--->3FeOCl
42) NaCl+AgNO3--->NaNO3
+AgCl
43) HCl+NH3--->NH4Cl
44) 2Al+6HCl--->2AlCl3+3H2
45) Ca + 2HCl = CaCl2 + H2
46) CaCO3 + H2SO4 = CaSO4 + H20 + CO2
47) 3H2SO4 + 2Fe ---> Fe2(SO4)3 + 3H2
48) Mg3N2 + 3H2O ---> 3MgO + 2NH3
49) CH4+ O2 ---> CO2 + H2O
50) Cl2 + SO2 + H2O ---> HCl + H2SO4
If I have repeated any equation, please do tell me.
Hope this helps you dear!!
Explanation:
You have two cubes that have the same color and volume. You drop them in water, one sinks and the other floats. What property did you demonstrate for the two substances? And, is it a chemical or physical property?
Answer:
The difference between a physical reaction and a chemical reaction is composition. In a chemical reaction, there is a change in the composition of the substances in question; in a physical change there is a difference in the appearance, smell, or simple display of a sample of matter without a change in composition. Although we call them physical "reactions," no reaction is actually occurring. In order for a reaction to take place, there must be a change in the elemental composition of the substance in question. Thus, we shall simply refer to physical "reactions" as physical changes from now on.
Introduction
Physical changes are limited to changes that result in a difference in display without changing the composition. Some common changes (but not limited to) are:
Texture
Color
Temperature
Shape
Change of State (Boiling Point and Melting Point are significant factors in determining this change.)
Physical properties include many other aspects of a substance. The following are (but not limited to) physical properties.
Luster
Malleability
Ability to be drawn into a thin wire
Density
Viscosity
Solubility
Mass
Volume
Any change in these physical properties is referred to as a physical change. For further information, please refer to Properties of Matter.
Chemical changes, on the other hand, are quite different. A chemical change occurs when the substance's composition is changed. When bonds are broken and new ones are formed a chemical change occurs. The following are indicators of chemical changes:
Change in Temperature
Change in Color
Noticeable Odor (after reaction has begun)
Formation of a Precipitate
Formation of Bubbles
Note: When two or more reactants are mixed and a change in temperature, color, etc. is noticed, a chemical reaction is probably occurring. These are not definite indicators; a chemical reaction may not be occurring. A change in color is not always a chemical change. If one were to change the color of a substance in a non-chemical reaction scenario, such as painting a car, the change is physical and not chemical. This is because the composition of the car has not changed. Proceed with caution.
Bobbye wants to know how his speed affect the amount of time it takes to stop at a stop sign. Each time he performs a trial, he will change the speed that he is driving to see how it affects the amount of time it takes to stop. Independent Variable: Dependent Variable: Controlled Variables:
Answer:
The correct answer is -
Independent Variable: change of speed
Dependent Variable: time takes to stop
Controlled Variables: stop at a stop sign
Explanation:
To know the effect of the speed to take the time to stop at a stop sign Bobbye perform this exercise where he changes the speed at each time that he is driving to know the time it takes to stop at a stop sign. There is a change that takes place purposely is in the speed of driving so it is an independent variable as the independent variable is a variable that is manipulated in an experiment or investigation.
The time it takes to stop is the factor that depends on the speed so it is the dependent variable as the dependent variable is the variable that depends on the independent variable.
The control variable remains the same or constant in an investigation which is stoping at a stop time irrespective of speed.
After the addition of the iron, the test tube now contains iron (II) sulfate solution and copper
particles. The iron has become part of a
A
compound with the sulfate, which must be separated through chemical methods
B
compound with the sulfate, which can be separated through physical methods
C.
mixture with the sulfate, which must be separated through chemical methods
D. mixture with the sulfate, which can be separated through physical methods
The iron has become part of a A. compound with the sulfate, which must be separated through chemical methods.
Iron (II) sulfate is also referred to as ferrous sulfate is a reducing agent. The hydrates form is used for the treatment of iron deficiency.
It should be noted that a chemical change is involved in the formation of iron (II) sulfate. It can't be separated by physical means and isn't reversible.
In this case, iron (II) sulfate will be separated by chemical methods.
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Iron sulfate is a compound which can be separated through chemical methods.
Iron is present in a compound form with the sulfate, which must be separated through chemical methods because both iron and sulfate reacts with each other through making of chemical bonds with each other. Those elements that combine with each other chemically at a fix ratio can be separated from each other through chemical methods.
While on the other hand, in mixture substances combine with each other physically so they can be separated from each other through physical methods so we can conclude that iron sulfate is a compound which can be separated through chemical methods.
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Does anyone know how to write on a pdf file? I have to do an assignment for chemistry, but i don’t know how to write on it through my laptop. I downloaded it but it still doesn’t really let me type or write on it. Help?
Go to the google marketplace and download pdf editor. it's free and it's amazing
Help plsss quickly!!!
PLEASE HELP!!!!!
a) Use your knowledge of atoms, bonding, and the periodic table to complete the chemical equation
and predict the products of the chemical reaction on your paper. Label this equation “Initial
Prediction.”
CH4 + O2 ----->___________
Answer:
{CH4 +2O2 ->CO2 + 2H2O}}}
Answer:
CH4 + 202----->CO2 + 2H2O
Hanrietta has a sample of a pure substance in a beaker. She heats the substance to a temperature of 100C. What will determine if the substance is a solid, liquid, or gas at 100C? .a. the amount of it that is contained in the beaker
. b. the height of the beaker containing it. c. the width of the beaker containing it. d. the strength of the forces between its atoms
Answer:
d. the strength of the forces between its atoms
Explanation:
The strength of the intermolecular forces between the atoms of the pure substance will determine the type of substance it is when heated to 100°C.
A pure substance are elements and compounds. They are usually homogenous in all parts with a definite composition. A solid is made up of strong intermolecular forces that are very difficult to break. Liquids have fairly weak bonds between them. Gases have little to no intermolecular attraction. Using these parameters, we can see that the property of the substance at this temperature will determine its physical state.Considering the passage about crude oil, why is distillation the main process for separating the contents of crude oil? Crude oil is a homogeneous mixture. Crude oil is a heterogeneous mixture A major byproduct of crude oil is gasoline.
Answer:
Crude oil is a homogeneous mixture.
Explanation:
I got it right.
Answer: Crude oil is a homogeneous mixture.
Explanation: im doin edge
To soften cloths in the wash it is recommended to use 2.0 g of sodium borate per liter of water. If a filled washing machine holds 10 L of water and the correct amount of sodium borate per liter is added, what is the concentration in percent mass/volume of the solution?
% m/v of the solution = 0.2%m/v
Further explanation[tex]\tt Percent~m/v=\dfrac{mass~solute(g)}{volume~solution(ml)}\times 100\%[/tex]
or
% m/v = g solute / 100 ml solution
Concentration : 2 g sodium borate / L water
For 10 L⇒20 g Sodium borate
[tex]\tt \%m/v=\dfrac{20~g}{10,000~ml}\times 100\%\\\\\%m/v=0.2\%[/tex]
Which of the following statements about elements and atoms is true?
Answer:
the first one
Explanation:
How many electrons are located in the outermost energy level in the Bohr model of a boron atom? hint it not 4
4
3
2
1
Which of the following is NOT an example of a Heterogeneous Mixture?
1.table salt
2.Chex Mix
3.Vegetable Soup
4.Beach Sand
Answer:
pretty sure its table salt
Answer:
The answer would be vegetable soup i think.
Hope this helps :D
gold has a density of 19.3 g.cm3. Iron pyrite, commonly known as fools gold because of its colour, has a density of 5.02 g/cm3. Suppose that you find a golden solid that has a mass of 25.04g and a volume of 4.99 cm3. have you found gold or iron pyrite? pls help!!
Answer:
Compare qualitative and quantitative physical properties. Use examples of properties listed in Tables 4.2 and .3 as part of your answer
can be observed and described without detailed measurement, usually obvious and easy to observe. For example, odor can be described as sweet, pungent and or moldy.
Quantitative Physical Properties
can be measured and assigned a value, for example melting points and boiling points could be considered a quantitative physical property
Why is the melting point considered a physical property?
Because you are not creating a new substance in the process of melting it. If you melt gold, it will still remain gold just in a different form.
What property determines the choice of material that is used for the inside of an electrical wire and the material that is used for the outside of the wire?
The conductivity of the material will determine the material needed for both the inside and outside of an electrical wire. The electrical wires ability to conduct electricity, or give off heat will allow us to have an idea as to what type of material may insulate or protect the electrical wire.
When might a large volume of material have little mass?
When the material weighs less. For example, Styrofoam with the volume of 500 cm (cubed) has a smaller mass in comparison to 500 cm (cubed) of Gold. Since the density in Styrofoam is little, the mass of it would also be little in contrast to an element like gold, which has a higher density therefore it has a higher mass.
Gold has a density of 19.3g/cm (cubed). Iron pyrite, commonly known as fool's gold because of its color, has a density of 5.02g/cm (cubed). Suppose you find a golden solid that has the mass of 25.04g and a volume of 4.99 cm (cubed). Have you found gold or iron pyrite?
Do the math
The density of red wine vinegar is 1.01g/cm (cubed), and the density of olive oil is 0.92g/cm (cubed). A salad dressing consisting of these two ingredients was left sitting too long. The ingredients separated in the bottle. Which ingredient is in which layer?
do the math
Water is unique because the density of its solid, ice, is less than the density of its liquid. Describe how life would be if this were not true.
think about it and say it out loud
Match the term (Endothermic) with the correct definition
energy goes into the chemical and cool downs the surrounding area.
energy leaves the chemical and cools down the surrounding area
energy leaves the chemical and heats up the surrounding area
Answer:
energy goes into the chemical and cool downs the surrounding area.