Answer:
Number of moles in 20.5 grams of calcium (Ca) = 0.5 moles (Approx.)
Explanation:
Given:
Amount of calcium (Ca) = 20.5 grams
Find:
Number of moles in 20.5 grams of calcium (Ca)
Computation:
Number of moles = Gram weight / Atomic weight of substance
We know that, Atomic weight of calcium (Ca) is 40.078 u
Number of moles in 20.5 grams of calcium (Ca) = Amount of calcium (Ca) / Atomic weight of calcium (Ca)
Number of moles in 20.5 grams of calcium (Ca) = 20.5 / 40.078
Number of moles in 20.5 grams of calcium (Ca) = 0.511
Number of moles in 20.5 grams of calcium (Ca) = 0.5 moles (Approx.)
Which of the following statements describes
an exothermic reaction but not an endothermic
reaction?
A. Energy is destroyed during the reaction.
B.
Energy is used to form chemical bonds.
C. Energy is used to break chemical bonds.
D. Energy is released as heat during the reaction.
Answer:
Energy is released as heat during the reaction.
Answer:
D. Energy is released as heat during the reaction.
Explanation:
How many atoms of oxygen (o)are present 2naOH+H2SO4 2H2O+Na2SO4
Answer:
10
Explanation:
What is the first quantum number of the 3p¹ electron in aluminum,
1s²2s²2p63s²3p¹?
A. n=0
B. n = 1
C. n=3
D. n = 2
Quantum number of the 3p¹ electron in aluminum is n=3.
What is the quantum number?Quantum numbers in quantum physics and chemistry explain the values of conserved quantities in a quantum system's dynamics. Quantum numbers are quantities that can be precisely known at the same time as the system's energy and are related to the eigenvalues of operators that commute with the Hamiltonian and their corresponding eigenspaces. A base state of a quantum system is fully described by the specification of all of its quantum numbers, which can theoretically be measured collectively.
The quantization of numerous interesting observable quantities is a crucial component of quantum physics.
This specifically results in quantum numbers, though they may occasionally reach infinity, that take values in discrete sets of integers or half-integers. This sets quantum mechanics apart from conventional mechanics.
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What effect does light have on the growth of plants?
Select all that apply.
Light does not have any effect on a plant’s growth.
Light makes a plant’s stem grow shorter.
Light makes a plant’s leaves turn brown.
Light will make a plant’s leaves grow bigger.
Answer:
The answer is the last one only.
Explanation:
Light/sun gives energy and growth which makes the plants leaves/plant grow bigger.
Explanation:
Without the sun, plants wouldn't get the food that's needed to grow, reproduce and survive. plants need sunlight, water and carbon dioxide to live.
Which temperature would be most appropriate on a hot summer day: 0 Degrees Celsius, 35 Degrees Celsius, or 90 Degrees Celsius?
Which temperature would be most appropriate as a room temperature: -20 Degrees Celsius, 0 Degrees Celsius, or 20 Degrees Celsius?
A block of aluminum has a volume of 15mL and a mass of 45g. In this example what is aluminum's density?
A rectangular block of gold has a mass of 80g. The dimensions of the block are 2cm by 5cm by 4cm. From this information, calculate the density.
Answer:
1. For a hot summer day, 35 degrees Celsius is most appropriate.
2. For room temperature, 20 degrees Celsius is most appropriate.
3. Aluminum's density is found by dividing mass by volume. 45 / 15 = 3 g/mL. The density is 3 g/mL.
4. Volume is found by multiplying length x width x height. 2cm x 5cm x 4cm equals 40 cm. We then divide the mass by volume to find density. 80 / 40 = 2 g/cm³. The density is 2 g/cm³.
When guard cells are full, they bulge. This increases the
size of the gap between them and opens the hole in the
leaf.
Guard cell
Water and
oxygen
Carbon
dioxide
Guard cell
Which object is the best model of a guard cell?
Guard cells are the plant cells that are specialized to perform the gaseous exchange in the leaves. It can be best represented by the model of the water balloon.
What are guard cells?Guard cells are the part of the plant leaves and stem that are essential for the control and exchange of the water, oxygen, and carbon dioxide molecules from the cell environment to the surroundings.
It regulates the closing and the opening of the stomata that become curved when open to make a hole in the middle. When water is present inside the cells they swell making the cell look bulgy like the water in a balloon.
Therefore, the water balloon model best explains the guard cells.
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3.523 x 10^24 molecules of Mg(OH2) will need how many grams of H3PO4 in the reaction below
H=1.01 g/mol
P=30.97 g/mol
O=16.00 g/mol
3 Mg(OH)2 + 2 H3PO4 --------> 1 Mg3 (PO4 )2 + 6 H2O
Answer:
382.2g of H3PO4 are needed
Explanation:
Based on the reaction, 3 moles of Mg(OH)2 react with 2 moles of H3PO4.
To solve this question we must find the moles of Mg(OH)2 using Avogadro's number. Then, using the reaction we can find the moles of H3PO4 and its mass as follows:
Moles Mg(OH)2:
3.523x10²⁴ molecules * (1mol / 6.022x10²³ molecules) = 5.850 moles Mg(OH)2
Moles H3PO4:
5.850 moles Mg(OH)2 * (2 mol H3PO4 / 3 mol Mg(OH)2) = 3.90 moles H3PO4
Mass H3PO4:
Molar mass:
3H = 1.01g/mol*3 = 3.03
P = 30.97g/mol*1 = 30.97
4O = 16.00g/mol*4 = 64.00g/mol
3.03 + 30.97 + 64.00 = 98.00g/mol
3.90 moles H3PO4 * (98.00g / mol) =
382.2g of H3PO4 are needed17. A balloon contains 4.50 X 1022 atoms of helium gas. Calculate the mass of helium in
grams.
Answer:
1.08 grams
Explanation:
first, we need to find the number of moles
we divide 12.1/22.4=0.54 moles
we multiply the number of moles with the molecular mass 0.54x2=1.08g
The mass of the helium will be 0.296 g He.
What is mass?
The quantity of matter in a thing is measured by its mass. Grams (g) or kilograms (kg) are the most common units of mass measurement (kg).The quantity of matter is measured in terms of mass, regardless of where it is in the universe or the gravitational force acting on it.
Calculation of mass of helium:
It is given that, atom of He = 4.50 X [tex]10^{22}[/tex] , mass of He = 4 g.
4.50 X [tex]10^{22}[/tex] atoms He × 1 mole He / 6.02 × [tex]10^{23}[/tex] atom He = 0.0914 mol He.
Now, apply the conversion formula:
Moles He × grams He / 1 mole He = grams He.
Put the value of given data in above formula.
0.0914 mol He × 4 g / 1 mol He = 0.296 g He.
Therefore, the mass of the helium will be 0.296 g He.
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What are the uses of the metal Magnesium?
Answer:
use of sterile injections for clearanti bodies
Explanation:
Answer:
Hello There!!
Explanation:
They can be used in making products that make it lightweight such as in power tools and luggages.
hope this helps,have a great day!!
~Pinky~
Which type of lipids/fats increase cholesterol levels in the
blood?
saturated lipids
unsaturated lipids
Answer:
In humans, saturated fat intake increases LDL cholesterol in comparison with all nutrients except trans fats [2•]. Because saturated fat also increases high-density lipoprotein (HDL) cholesterol, the total cholesterol (TC) to HDL cholesterol ratio (a risk marker for CVD) is not altered. I would like Brainleist please!
Explanation:
if you answer this correctly ill give you brainliest (HINT IT'S NOT D)
Answer: I believe the answer is A - the total growth of the plants.
Explanation: The total growth of the plants depends on the hours of sunlight. So, this would be your dependent variable, while the hours (amount) of sunlight would be your independent variable.
Answer:
A
Explanation:
since that's what's being measured
what is the number of moles of water in 100 g of vinegar?
Answer:
The number of moles of water in 100 g of vinegar is 0.47 moles.
Explanation:
The ratio of the elements in a binary ionic compound are based on the element's _______________.
A. oxidation number
B. mass number
C. total number of neutrons
Two metals (Metal A and Metal B) are both exposed to a laser which emits photons that have a greater energy than the work function of both metals. Metal A has a smaller work function than Metal B. Therefore, The de Broglie wavelength of the electrons produced from metal A will be ____________ those from metal B.
The number of electrons produced from metal A will be ____________ the number produced from metal B.
Answer:
shorter than
equal to
Explanation:
Let us go back to the Einstein photoelectric equation;
KE = E - Wo
Where
KE = kinetic energy of the photoelectron
E = energy of the incident photon
Wo = work function of the metal
But KE = 1/2mv^2
Thus the velocity of the emitted photoelectron is determined by the kinetic energy of the emitted photoelectron.
Since the work function of metal A is smaller than that of metal B, the kinetic energy of photoelectrons emitted from metal A is greater than that of photoelectrons emitted from metal B . Therefore, the velocity of electrons from metal A is greater than those from metal B.
From de Broglie relation;
λ = h/mv
Where;
λ = de Broglie wavelength
h = Plank's constant
m = mass
v = velocity
Metal A producing electrons with greater velocity will lead to a shorter de Broglie wavelength compared to those from metal B.
The number of photoelectrons ejected is determined by the intensity of the photons and not the energy of the incident photons or the work function of the metals. Since the two metals are exposed to the the same laser, equal number of photoelectrons are produced for metals A and B.
What's the most unreactive metal?
Answer:
gold and platinum
Explanation:
Very unreactive metals, such as gold and platinum, are found in the Earth's crust as pure metals. These are called native metals.
should I go ahead and complete the last assignment of the 9th grade? I got a week till I have to turn it in. I can complete it in about an hour. What do yall think?
Answer:
I think you should, after you complete it and turn it in then you have nothing else to worry about! Get it out the way and do it :)
Answer:
Heres my advice. Dont wait exactly until the deadline.
Explanation:
If its the last assignment, be lazy. do what you want! but, if you only have a week to turn it in then do it on the 4th day then turn it in.
. A 300 kg Blue car is moving rightward at 3 m/s, about to collide with a 100 kg Red car. Adjust the
velocity of the Red car so that the total momentum of the system is 800 kg m/s. (Adjust the velocity
of the Red car so that the sum of the momentum of the Blue car and the momentum of the Red car
equal 800 kg m/s.) What happened?
Answer:
The velocity of the red car is 1 m/s.
Explanation:
Given that,
The mass of blue car, m₁ = 300 kg
The mass of red car, m₂ = 100 kg
The velocity of Blue car, v₁ = 300 kg
The total momentum of the system, p = 800 kg-m/s
The momentum of an object is given by :
p = mv
So,
[tex]m_1v_1+m_2v_2=p[/tex]
Where
v₂ is the velocity of red car. So,
[tex]v_2=\dfrac{p-m_1v_1}{m_2}\\\\v_2=\dfrac{800-300\times 3}{100}\\\\v_2=-1\ m/s[/tex]
So, the velocity of the red car is 1 m/s.
Which electron configuration represents a transition element?
01s²2s²2p³
01522s22p635²
1s²2s²2p63s²3p64s²3d7
1s22s22p63s23p64s²3d¹04p4
The electronic configuration which represents a transition element is 1s²2s²2p⁶3s²3p⁶4s²3d⁷
What is a transition element?Transition elements are placed between the metallic S-block elements and nonmetallic P-block elements in the periodic table. They are D-block elements and have features similar to both metals and nonmetals, to some extent. This is why they are called transition elements.
One remarkable feature of these elements happens during the addition of electrons to them. Contrary to S and P-block elements, electrons are added to the penultimate shell, not the last shell. These elements often feature partially filled d-orbitals and have multiple oxidation states.
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Which statement accurately depicts the mass and volume of a gas according to the kinetic molecular theory?
O Gases have no defined volume but a defined mass.
O Gases have no defined volume and no defined mass.
O Gases have a defined volume but no defined mass.
O Gases have a defined volume and a defined mass.
Answer: The statement, gases have no defined volume but a defined mass accurately depicts the mass and volume of a gas according to the kinetic molecular theory.
Explanation:
According to the kinetic molecular theory there exists constant motion between the particles of gas and perfectly elastic collisions also exist there between these particles.
Some postulates of Kinetic molecular theory are as follows.
1). The exists constant random motion in the particles of a gas.
2). There is negligible combined volume but a definite mass.
3). There exists no force of attraction between the particles of a gas.
4). Collisions which take place are completely elastic in nature.
Thus, we can conclude that the statement, gases have no defined volume but a defined mass accurately depicts the mass and volume of a gas according to the kinetic molecular theory.
The statement that accurately depicts the mass and volume of a gas according to the kinetic molecular theory is that gases have no defined volume but a defined mass.
WHAT IS KINETIC MOLECULAR THEORY?The kinetic molecular theory of gases states constant motion exists between the particles of gas and perfectly elastic collisions also exist there between these particles.
The postulates of the kinetic molecular theory are as follows:
The exists constant random motion in the particles of a gas.There is negligible combined volume but a definite mass.There exists no force of attraction between the particles of a gas.Collisions which take place are completely elastic in nature.Based on these postulates, it can be said that gases have no defined volume but a defined mass.
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Every day, each person in Canada throws out about 2.2 kg of garbage. If the population of Canada is 31 900 000, the total mass of garbage that all Canadians throw out each day is
Answer:
70 180 000 kg
Explanation:
We can solve this problem by multiplying the amount of garbage each Canadian throws out each day (2.2 kg) by the number of Canadians:
2.2 kg/person * 31 900 000 persons = 70 180 000Thus according to this problem, all Canadians throw out 70 180 000 kg of garbage each day.
QUESTION 54
What is/are the reactant(s) of the chemical reaction shown?
CH4 (g) + 202 (g) → CO2 (g) + 2H20 (g)
O CH4 only
O 02 only
O CH4 and 02
O CO2 and H20
The process above is not a chemical reaction
Answer:
the answer is C.
Explanation:
CH4 and 02
Name three different properties you can test before and after a chemical reaction
Answer:
reactivity, flammability, and if they rust
Nothing. Finished my AP chem test n wanna give some points out
Answer:
Nice
Explanation:
Answer:
thanks girl
Explanation:
what is the molar mass of barium hydroxide
Answer:
171.34 g/mol
Explanation:
Ba molar mass = 137.328 g/mol
O molar mass = 15.999 g/mol * 2 = 31.9980 g/mol
H molar mass = 1.008 g/mol * 2 = 2.0160 g/mol
137.328 + 31.9980 + 2.0160 = 171.3420 = 171.34 g/mol
Explain how an incorrect of dietary information on high blood sugar could potentially affect the patient’s
Long-term (months or years) high blood sugar levels can cause irreversible harm to organs such the kidneys, blood vessels, eyes, nerves, and nervous system. Speak with your doctor or the diabetes care team if you frequently have hyperglycemia.
What effects could an extremely high blood sugar level have on us?If left untreated, having excessive blood sugar levels for an extended length of time might lead to major health issues. In addition to raising the risk of heart disease, stroke, kidney illness, vision issues, and nerve issues, hyperglycemia can harm the blood arteries that provide blood to essential organs.
What dietary requirements are impacted by diabetes?A high-fat, high-calorie, and high-cholesterol diet
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No Constant Variable
A 2.00L sample of gas at STP is heated to 500K and compressed to 200 kPa. What is
the new volume of the gas?
I’ll give you all my points
The new volume of the gas will be 1.85L.
The three gas laws are what?According to Boyle's Law, as pressure lowers, gas volume grows. According to Charles' Law, when the temperature rises, the volume of the gas also rises. Avogadro's Law also states that as the amount of gas increases, so does the volume of the gas.
Given, initial volume of gas V1 = 2L
initial temp T1 = 273K
initial pressure P1 = 101.3 kPa
final temperature, T2 = 500K
Final pressure, P2 = 200 kPa
let final or new volume be V,
now for a constant moles of gas,
by using ideal gas equation,
P1×V1/T1 = P2×V/T2
101.3×2/273 = 200×V/500
202.6/273 = 2V/5
V = 0.742×5/2
V = 1.85 L
The new volume of the gas will be 1.85L.
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what do animals use for energy in food
A. GROWTH
B. REPAIR
C. MOTION
D. PHOTOSYNTHESIS
WILL MARK BRAINLIEST!
Stoichiometry DBA
1. 33 grams of Calcium Sulfate reacts with 28 grams of Aluminum Phosphate to form Calcium
phosphate and Aluminum Sulfate
Write balanced equation here -
2. Which of the two reactants will limit the production of Calcium Phosphate. Show work here.
3. How much of the Aluminum Sulfate would be produced? Show work here. 4. 44 grams of Zinc Nitrate reacts with 59 grams of Iron(III) Hydroxide to form Zinc Hydroxide
and Iron(III) Nitrate.
Write balanced equation here -
5. Which of the two reactants will limit the production of Iron(III) Nitrate . Show work here.
6. How much excess reactant will you have left over?
Answer:
Ca3(PO4)2..... the formula for Calcium phosphateIn a nuclear fission reaction, a freely moving neutron is introduced to a
nuclear fuel, such as uranium-235. What happens next?
O A. A neutron is absorbed by an atom's nucleus.
B. The neutron breaks apart.
O C. Heat is released by the neutron.
D. The nucleus becomes unstable.
The nucleus becomes unstable when a freely moving neutron is introduced to a nuclear fuel.
What is Nuclear fission?This is a reaction in which the nucleus of an atom splits into two or more smaller nuclei.
This reaction produces more neutrons and the nucleus becomes unstable when a freely moving neutron is introduced to a nuclear fuel to form fission fragments.
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pls i need help with this
Answer:
C
Explanation:
A physical change is one in which no new substance is formed. The moistening of food by saliva is purely a physical change because no new substance is formed in the process.
A chemical change leads to the formation of a new substance. The action of the enzyme converts starch into sugar which means that a new substance is formed. This is a chemical change.