Answer:
150 molecules of oxygen
Explanation:
Need help with #1 and #2
Answer:
To calculate half life, divide original value by 2.
1.
FOUR HALF LIVES = divide original value by 2, 4 times.
40÷ 2 = 20
20 ÷ 2 = 10
10 ÷ 2 = 5
5 ÷ 2 = 2.5g
2. AFTER TEN DAYS (TWO HALF LIVES)
140 ÷ 2 = 70
70÷ 2 = 35g
AFTER TWENTY DAYS (FOUR HALF LIVES)
140 ÷ 2 = 70
70 ÷ 2 = 35
35 ÷ 2 = 17.5
17.5 ÷ 2 = 8.75g
In a movable pulley system, where does the other effort come from?
Answer:
In a movable pulley system, where does the other effort come from? is carried by this end of the rope. This means that the structure (ceiling) does half the effort.
Explanation:
.
If the Moon orbited Earth twice as fast, how many high tides would occur in one day?
Four high tides would occur in one day, if the moon orbited Earth twice as fast.
What are high tides?The tide when the water is at its greatest elevation.
At the moment, high tides occur twice a day. So if the moon orbits the earth twice as fast, high tides will occur twice as many, which means four times a day.
High tides occur 12 hours and 25 minutes apart. It takes six hours and 12.5 minutes for the water at the shore to go from high to low, or from low to high.
The best-known effect of the moon is its gravitational pull on Earth's oceans, which results in two high tides and two low tides every day.
But if the moon were half the distance from Earth as it is now, the tides would be eight times higher.
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how many valence electrons does P have?
Answer:
5 valence electrons
Explanation:
Phosphorus is in group VA so it has 5 valence electrons and Oxygen is in group VIA so each oxygen has 6 valence electrons.
An atom of an element with atomic number 48 and mass number 120 contains
A. 48 protons, 48 electrons, and 72 neutrons
B. 72 protons, 48 electrons, and 48 neutrons
C. 120 protons, 48 electrons, and 72 neutrons
D. 72 protons, 72 electrons, and 48 neutrons
Option 5
Answer:
a
Explanation:
proton remains same as the atomic number
electron remains same as the atomic number
Mass no.- atomic no. = Neutrons
What is the frequency of red light with a wavelength of 645 nm?
Answer:
4.64E14
Explanation:
First convert 645 nm to m = 6.4500E-7m. The equation for finding v with these values is the speed of light/wavelength. so 2.998E8/6.4500E-7m.
so your v or frequency would equal 4.64E14
Fun fact you know this is visible light because the visible light range is within the E14 range.
.
You should be able to
these groups on the periodic table, and know their
properties.
Answer:
The vertical columns on the periodic table are called groups or families because of their similar chemical behavior. All the members of a family of elements have the same number of valence electrons and similar chemical properties.
Explanation:
I HOPE NAKATULONG PO AKO:)PA BRAINLEST NLNG PO SANA:(IN 4Ca(OH)2 how many atoms of calcium.
This substance contains 4 atoms. Ca = 1. O = 1. H = 2 because H2 means two atoms of the substance it comes after.
How does density affect sinking and floating in water?
Answer:
Density is a measure of how heavy something is compared to its size.
If an object is more dense than water it will sink when placed in water, and if it is less dense than water it will float.
Density is a characteristic property of a substance and doesn’t depend on the amount of substance.
Explanation:
If you compared the weight of wood and an equal amount, or volume, of water the sample of wood would weigh less than the sample of water. This means that wood is less dense than water. Since wood is less dense than water, wood floats in water, no matter how big or small the piece of wood is.
A student might want to know why a boat made out of steel can float when steel is more dense than water. This is not an easy question and requires a different approach than what students have seen so far. We do not necessarily recommend the following explanation for 5th graders but here is the idea:
An object floats when it displaces a volume of water that has a mass equal to the mass of the object. So if a material like steel is shaped into a boat and made larger and larger, it will displace more and more water. When it is large enough to displace a volume of water that has a mass equal to the mass of the boat, the boat will float.
15.24. Calcium hydroxide, also known as slaked lime, is used in industrial processes in which low concentrations of base are required. Only 0.16 g of Ca(OH)2 dissolves in 100 mL of water at 25°C. What is the concentration of hydroxide ions in 250 mL of a solution containing the maximum amount of dissolved calcium hydroxide?
The concentration of the hydroxide ions, OH¯ in 250 mL of the solution containing the maximum amount of dissolved calcium hydroxide is 0.01728 M
We'll begin by calculating the number of mole of in 0.16 g of Ca(OH)₂. This can be obtained as follow:
Mass of Ca(OH)₂ = 0.16 g
Molar mass of Ca(OH)₂ = 40 + 2[16 + 1] = 74 g/mol
Mole of Ca(OH)₂ =?Mole = mass / molar mass
Mole of Ca(OH)₂ = 0.16 / 74
Mole of Ca(OH)₂ = 0.00216 mole Next, we shall determine the molarity of the stock solution of Ca(OH)₂.Mole of Ca(OH)₂ = 0.00216 mole
Volume = 100 mL = 100 / 1000 = 0.1 L
Molarity of Ca(OH)₂ =?Molarity = mole / Volume
Molarity of Ca(OH)₂ = 0.00216 / 0.1
Molarity of Ca(OH)₂ = 0.0216 MNext, we shall determine the molarity of the diluted solution. This can be obtained as follow:Volume of stock solution (V₁) = 100 mL
Molarity of stock solution (M₁) = 0.0216 M
Volume of diluted solution (V₂) = 250 mL
Molarity of diluted solution (M₂) =?M₁V₁ = M₂V₂0.0216 × 100 = M₂ × 250
2.16 = M₂ × 250
Divide both side by 250
M₂ = 2.16 / 250
M₂ = 0.00864 MThus, the molarity of the diluted solution is 0.00864 M
Finally, we shall determine the concentration of the hydroxide ions, OH¯ in the diluted solution. This can be obtained as follow:Ca(OH)₂(aq) —> Ca²⁺(aq) + 2OH¯(aq)
From the balanced equation above,
1 mole of Ca(OH)₂ contains 2 moles of OH¯
Therefore,
0.00864 M Ca(OH)₂ will contain = 2 × 0.00864 = 0.01728 M OH¯
Thus, the concentration of the hydroxide ions, OH¯ in 250 mL of the solution containing the maximum amount of dissolved calcium hydroxide is 0.01728 M
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70 points!!!! will mark the brainliest,
ANSWER ASAP PLS??????????????
Answer:
I believe it's A.
Explanation:
Answer:
option C
Explanation:
There are 2 types of changes
Physical change :- The physical properties are changed and its temporary.Chemical change :- The chemical properties are changed and its permanent.Which one please help
Answer:
density is mass more mass more density and same as volume
Someone pls help me I will make you brain
Answer:
a
Explanation:
i took test
Discussion Question: Your classmate said,
"I think Gold is a pure substance that can't be broken down any further
Do you agree or disagree with this statement. Explain your reasoning using clues from the statement and the periodic
table.
Answer:
yes gold is pure
Explanation:
3. If you drive for 3 hours at a constant speed and make it 400 miles, how fast did you go?
Answer:
133.333333333 mph
or
214.5791999994464 kph
Explanation:
Answer:133.333333333 mph
or
214.5791999994464 kph
Explanation:
What are the most common sources of nitrates that lead to unhealthy water systems
Answer:
Sources of nitrate that can enter your well include fertilizers, septic systems, animal feedlots, industrial waste, and food processing waste.
Question 4 (2 points)
(02.04 MC)
Jackson is making dinner and is trying to dissolve salt into a pot of water. The salt is dissolving slowly. What should Jackson do to speed up the
rate of dissolving? (2 points)
O.
Ob
Oc
He should put larger salt particles in the water.
He should hear the water to a higher temperature.
He should completely stop stirring the pot of water.
He should slow down the speed he is stirring the pot
Od
Question 5 (2 points)
(02.04 MC
ribed below
Answer:
B. He should heat the water to a higher temperature.
Explanation:
Tiny particles that make up water and salt vibrate at higher speeds in hotter temperatures, which mixes the salt and water faster. This causes salt to dissolve much faster.
A container contains three gases. If the partial pressure of carbon dioxide is 0.50 atm, the partial pressure of nitrogen is 0.30 atm, and the partial pressure of methane is 0.40 atm, what’s the total pressure inside the container?
Answer:
1.20 atm
Explanation:
A container contains three gases. If the partial pressure of carbon dioxide is 0.50 atm, the partial pressure of nitrogen is 0.30 atm, and the partial pressure of methane is 0.40 atm, what’s the total pressure inside the container?
Do not let chemistry questions SCARE you! The TOTAL means
ADD THEM UP.
You can do this without a scientific calculator :-)
0.50 +0.30 + 0.40 = 1.20 atm
between a water molecule and an ethanol molecule, a hydrogen bond can occur between a lone pair of electrons on the _____a_____ in water and the _____b_____ of an ethanol molecule.
Answer:
They will form a hydrogen bond with the oxygen atom and the polar hydrogen atom.
Between a water molecule and an ethanol molecule, a hydrogen bond can occur between a lone pair of electrons on the Oxygen and a Hydrogen in water and the Polar hydrogen of an ethanol molecule.
What is Hydrogen bond ?Hydrogen bonding is an interaction involving a hydrogen atom located between a pair of other atoms having a high affinity for electrons.
It is a bond is weaker than an ionic bond or covalent bond but stronger than van der Waals forces.
In the given question, They will form a hydrogen bond with the oxygen atom and the polar hydrogen atom.
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Help meeeeeeeeeeeeeee
AMSWER :
CHEMICAL FORMULA :
• WATER - H2O
• CARBONDIOXIDE - CO2
• SODIUM HYDROXIDE - NaOH
• SULPHURIC ACID - H2SO4
• SODIUM CHLORIDE - NaCI
• SODIUM BICARBONATE - NaCHO3
Where do most metabolic reactions occur?
all of the above
O plasma membranes
O nucleus
O cytoplasm
Answer:
CYTOPLASM
Explanation:
MOST REACTION REQUIRE WATER TO OCCUR
SINCE ENZYME WORK BEST WHEN DISSOLVED IN WATER
WATER IS PRESENT IN CYTPLASM HENCE IT IS MAIN SITE OF MEABLIC REACTIONS
CONNECT IT
Relate how a household sponge and water can be used to model
the concept of an unsaturated solution, a saturated solution, and a supersaturated
solution.
The sponge is unsaturated when it is taking in more water. It becomes saturated when it stops taking in water. It is supersaturated when water starts oozing out from the sponge.
A saturated solution contains just as much solute as it normally hold at a particular temperature. An unsaturated solution contains less solute than it can normally hold at a particular temperature. A supersaturated solution contains more solute than it can normally hold at a particular temperature.
We can use a sponge to model these three scenario as follows;
Water continues to enter into the sponge when it is unsaturated, this continues until the sponge becomes saturated with water and takes in no more water. When the sponge becomes supersaturated, water begins to ooze out from the sponge because it can no longer hold more water.
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A 1.044 g sample contains only vitamin C (C6H8O6) and sucralose (C12H19Cl3O8). When the sample is dissolved in water to a total volume of 33.0 mL, the osmotic pressure of the solution is 3.69 atm at 295 K. What is the mass percent of vitamin C and sucralose in the sample?
Answer:
Refer the attachment for answer..
hope it helps you..
NEED HELP ASAP!!!!!!!!!!!!!!!!!!!!!!
A noble gas has 8 electrons between the p and s orbitals of the outer shell. Helium is the exception because it only has two electrons.
∴ 1s²2s²2p⁶ is the noble gas (neon)When does an electrically charged object attract another object?
A. When one object is far away from the other
B. When each object is negatively charged
C. When the objects are oppositely charged
D. When each object is positively charged
Answer:
C. When the objects are oppositely charged
Explanation:
Electrostatic interactions are commonly observed whenever one or more objects are electrically charged. Two oppositely-charged objects will attract each other. A charged and a neutral object will also attract each other. And two like-charged objects will repel one another.
From Bing, this is not my work
Answer:C
Explanation:
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC! lol i think its c
what if water didnt have a negative charge?
Answer:
Explanation:
It would be positively charge
If you have two pistons in a system, which exerts the larger force?
Answer:
The larger piston
Explanation:
(i just took the same test)
what does the theory of plate tetonics state
Answer:
Plate tetonics theory is the idea that different tectonic plates, are constantly moving and changing the surface of our Earth. They can move in three ways, convergent, divergent, and transform. Seafloor Spreading is like an example of divergent movement. When the plates diverge from each other it can create various changes such as creating a new sea floor. You can use seafloor spreading as an example of the plate tetonics theory.
Explanation:
A mixture of hydrogen, nitrogen, and water vapor has a total pressure of 864 mmHg. The partial pressure of hydrogen is 220 mmHg and that of nitrogen is 410 mmHg. What is the partial pressure of water vapor?
Answer:
As per Dalton's law of Partial pressure,
The total pressure of a mixture of gases is equal to sum of partial pressure of individual components of the mixture.
So,P=P_H+P_N+P_WP=P
H
+P
N
+P
W
\implies 864\ mm=220\ mm+410\ mm+P_W\implies⟹864 mm=220 mm+410 mm+P
W
⟹ P_W=864-630=234P
W
=864−630=234 mm of Hg.
Explanation:
"The partial pressure of water vapor is 234 mm Hg."
What is partial pressure?
The force that a gas exerts is known as partial pressure. The total pressure of a mixture of gases is equal to the sum of their partial pressures.
Partial pressure can be calculated by using the formula: [tex]P_{Total} =P_{N} +P_{H} +P_{H}[/tex]
Puts the value of given data in above equation.
[tex]Px_{W} =864-410-220\\\\= 234 mm Hg[/tex]
To know more about partial pressure.
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The "clusters" of Democritus are like what kind of material
that we know of today?