Answer: a.4
Explanation:
n=1
h=3
The statement “Matter cannot be created or destroyed during a chemical change.” is known as
What is the atomic mass of an atom that contains 28 protons, 28 electrons, and 30 neutrons?
86
28
58
56
Why does lowering the pressure cause a liquid to boil?
A. It becomes easier for molecules to escape.
B. It pushes molecules out of the liquid.
C. It causes the temperature to rise.
D. It changes the volume of the liquid.
Lowering the pressure in a container will cause the liquid in the container to boil faster because it becomes easier for the molecules to escape.
What causes boiling?Boiling happens when the vapor pressure of a liquid equals the atmospheric pressure.
By lowering the atmospheric pressure, the vapor pressure of a liquid takes a lower time to equal the atmospheric pressure.
Thus, it becomes easier for the molecules of the liquid to escape from each other.
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About how old is the Sun?
1.2 billion years
4.6 billion years
6.4 billion years
8.2 billion years
Answer:
B : 4.6 billion years
Credits go to the person above me.
;)
Explanation:
EDGE 2021
The sun is about 4.6 billion years old. Therefore, option (B) is correct.
What is the sun made of?The Sun is made primarily of the elements hydrogen and helium. They account for 74.9% and 23.8% mass of the Sun in the photosphere. All heavier elements, called metals account for less than 2% of the mass, with oxygen (<1%), carbon (0.3%), neon (0.2%), and iron (0.2%) being the most abundant.
The hydrogen and helium in the Sun would have been produced by Big Bang nucleosynthesis and the heavier elements were produced by former generations of stars before the Sun was formed.
The amount of helium and its location within the Sun has gradually changed over the past 4.6 billion years. The proportion of helium has raised from about 24% to 60% due to fusion, and some of the He and heavy elements have settled from the photosphere toward the center due to gravity.
Therefore, the age of the sun is about 4.6 billion years.
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Which molecule is Polar
HF
SiBr4
CO2
CH20
Answer:
Polar molecules have a non-zero net dipole moment. Both CO2 and H2O have two polar bonds. However the dipoles in the linear CO2 molecule cancel each other out, meaning that the CO2 molecule is non-polar. The polar bonds in the bent H2O molecule result in a net dipole moment, so H2O is polar.
Explanation:
Earth is the only planet to have ___ on it's surface?
Answer:
consistent
(stable bodies of liquid water)
What is an atomic number? An atomic mass?
Answer:
The atomic number is the number of the elements inside the periodic table and the mass is the weight or a number under the elements.
Explanation:
Correct me if I am wrong
Answer:
Atomic number
The number of protons in the nucleus of an atom.
Atomic Mass
The mass of an atom of a chemical element expressed in atomic mass units.
Helpppppppppppppppppp
the answer is deceleration.
Balancing C10H16 + Cl2 > C + HCl
brainy ki maa ki chut bhag bakwas aap
Which group in the food chain uses the energy of the sun to create its own food A consumers B predators C producers D prey
Answer:
C producers
Explanation:
All food chains start with energy from the sun. This energy is captured by plants. Thus the living part of a food chain always starts with plant life and ends with an animal. Plants are called producers because they are able to use light energy from the sun to produce food (sugar) from carbon dioxide and water.
Among the alkaline earth metals in Group 2A/A, which is more reactive - beryllium (element 4) or strontium (element 38)?
Answer:
Group 2A (or IIA) of the periodic table are the alkaline earth metals: beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra). They are harder and less reactive than the alkali metals of Group 1A.
Explanation:
Define unbalanced forces(giving Brainly)
Answer:
Unbalanced forces are forces whose net amount is not zero.
This can take place when two equal forces are acting in the same direction or opposite direction but with different forces.
Unbalanced forces make some change in the position of the object on which force is exerted.
Answer:
This can take place when two equal forces are acting in the same direction or opposite direction but with different forces.
Unbalanced forces make some change in the position of the object on which force is exerted.
Small children are occasionally injured when they try to inhale helium from a compressed helium tank. If a small child tries to transfer the contents of a 5.0 L tank of helium at a pressure of 125 atm and a temperature of 20⁰C into its lungs, how many moles of gas would the child inhale?
Answer:
26.0 moles
Explanation:
Given the formula;
PV =nRT
P= pressure of the gas
V = volume of the gas
n = number of moles of the gas
R = gas constant
T = temperature
n = PV/RT
n = 125 * 5/0.082 * (20 + 273)
n = 625/24.026
n = 26.0 moles
I NEED HELP :)
A train travels 76 miles in 1 7/12 hours. What is its average speed in miles per hour?
Answer:
48 mph
Explanation:
total time= 19/12 hr
distence- 76 miles
speed- D/T=76/19/12
which is 48mph
if my answer helps please mark as brainliest.
Answer:
pretty sure its average speed in miles per hour is 48
Explanation:
I just took 76 and divided it by 1 7/12 and got 48
6.
When an oxygen atom forms its most common ion, it
a) gains one electron.
b) gains two electrons.
c) loses one electron.
d) loses two electrons.
Answer:
gains two electron!
Explanation:
When a barium atom forms its most common ion, it gains two electron!
A block of aluminum occupies a volume of 15.0 mL and weighs 40.5 g. What is its density?
Answer: d=2.70 g/mL
I think
Convert 8.00 x 1020 molecules of H2 to moles.
Answer:
1.33 x 10^-3 mol H2
Explanation:
? mol H2 = 8.00 x 1020^20 molecules H2 x 1 mol H2/6.02 ! 1023 molecules H2 = 1.33 x 10^-3 mol H2
Hope that helps!
8.00 x 10²⁰ molecules of H₂ present in 1.33 x 10⁻³ mole of H₂.
What is mole?Mole is used to define the amount of quantity of any substance and 1 mole equals to the 6.023 × 10²³ elementary entities or atoms in it.
According to the question:
1 mole of H₂ = 6.023 × 10²³ molecules of H₂
or 1 molecules of H₂ = 1 mole of H₂ / 6.023 × 10²³ molecules of H₂
To convert 8.00 x 10²⁰ molecules into mole we calculate as follow:
x mole of H₂ = (8.00 x 10²⁰ molecules x 1 mole of H₂) / 6.023 × 10²³ molecules
x mole = 1.33 x 10⁻³ mole
Hence, 1.33 x 10⁻³ mole of H₂ consist 8.00 x 10²⁰ molecules.
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Determine the empirical and molecular formulas for a compound that has 10 pa a molar mass of 300 g/mol, and is 60.0% C, 12% H, and 28% N by composition.
Explanation:
the empirical formula is correct but I didn't got the question properly
Should the organism be considered a life-form?
Answer:
It is a synonym for "life form". Organisms are classified by taxonomy into groups such as multicellular animals, plants, and fungi; or unicellular microorganisms such as protists, bacteria, and archaea. ... Fungi, animals and plants are examples of kingdoms of organisms within the eukaryotes.
So yes, it should
Explanation:
Why does time seem to flow only in one direction?
Answer:
because time do not depend on direction. actually time is fake.nobody can stop it neither disturb it.it is in my view.
An enzyme is a catalyst.what does this mean?
Answer:
A catalyst is anything that alters the rate of the reaction same as an enzymes that adds to the process in a human body which stops working when a person has fever
Answer:
Enzymes are proteins functioning as catalysts that speed up reactions by lowering the activation energy. A simple and succinct definition of an enzyme is that it is a biological catalyst that accelerates a chemical reaction without altering its equilibrium. ... In the overall process, enzymes do not undergo any net change.
I hope it's helpful!
In a series circuit with 5 light bulbs if the battery has a current of 10 A how much current is in the first light bulb
Answer:
10A because they are series
What charge would you expect for an formed by S?
O-1
O-1
a 2
0-2
Look at picture
ASAP please will mark as brainlist don’t got much time
Answer:
in this the correct answer is option 2.
Zinc sulfide and oxygen gas react to form zinc oxide and sulfur dioxide. Determine the amount (g) of SO2 that should be produced in a reaction between 32.5 g of ZnS and 23.3 g of oxygen gas. What is the mass of the xs reactant?
Answer:
7.30g O₂ are in excess and 21.3g of SO₂ should be produced.
Explanation:
The reaction of Zinc sulfide (ZnS) with oxygen (O₂) produce ZnO and SO₂ as follows:
2ZnS + 3O₂ → 2ZnO + 2SO₂
Using this reaction we can find the amount of SO₂ produced converting the ZnS and O₂ to moles and finding limiting and excess reactant as follows:
Moles ZnS -Molar mass: 97.47g/mol-:
32.5g * (1mol / 97.47g) = 0.333 moles ZnS
Moles O₂ -Molar mass: 32g/mol-:
23.3g O₂ * (1mol / 32g) = 0.728 moles O₂
For a complete reaction of the 0.333 moles of ZnS are required:
0.333 moles ZnS * (3mol O₂ / 2mol ZnS) = 0.500 moles O₂.
As there are 0.728 moles of O₂, limiting reactant is ZnS and excess reactant is O₂.
The moles and mass of O₂ in excess are:
0.728mol - 0.500mol = 0.228moles O₂ * (32g / mol) = 7.30g O₂ are in excess
The produced mass of SO₂ -Obtained from the moles of ZnS- is:
0.333 moles of ZnS * (2mol SO₂ / 2mol ZnS) = 0.333 moles SO₂
0.333 moles SO₂ * (64.066g / mol) =
21.3g of SO₂ should be producedHow to convert the mass of a substance to the number of moles of a substance, and moles to mass
Answer:
Explanation:
To convert the mass to moles, divide the mass by the atomic weight of the element or compound.
To convert back to mass from the moles, multiply the moles by the atomic weight of the element or compound
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1. Fungal cells contain nuclei, which makes them classified as:
O eukaryotic
O saprophytic
O prokaryotic
O parasitic
Answer:
O eukaryotic
they have nucleus
10. What two effects can the wrong pH have on an enzyme?
Answer:
A pH environment has a significant effect on an enzymes. It can affect the intramolecular forces and change the enzyme's shape -- potentially to the point where it is rendered ineffective. With these effects in mind, typical enzymes have a pH range in which they perform optimally.
Explanation:
I hope this helps you.
Which of the following groups of elements are likely to be radioactive? (5 points) a Actinides b Noble gases c Transition metals d BCNOs
Answer:
Actinides
Explanation:
They are defined as "any of the series of fifteen metallic elements from actinium (atomic number 89) to lawrencium (atomic number 103) in the periodic table. They are all radioactive, the heavier members being extremely unstable and not of natural occurrence"
Answer:
Actinides
Explanation:
Actinides are radioactive and human-made elements.
If a sample of 0.500 moles of hydrogen sulfide (H2S) was reacted with excess concentrated sulfuric acid, how many moles of sulfur dioxide (SO2) would be produced?
Answer:
2.00
Explanation:
They said that was the answer.
If a sample of 0.500 moles of hydrogen sulfide H₂S was reacted with excess concentrated sulfuric acid then, number of moles of sulfur dioxide SO₂ would be produced are 2.00.
What are moles in gases?It is the ratio of mass of element in grams of a given compound and the molar mass of the element. In order to have balanced equation, we have to find the correct number of mole of SO₂. The reaction is
H₂S(g) + 3H₂SO₄ ⇄ 4H₂O(l) + 4SO₂
1 mole of H₂S react with excess of H₂SO₄ to give 4 moles of SO₂.
0.5 mole of H₂S react with excess of H₂SO₄ to give 4 x 0.5 =2.00 moles of SO₂.
Thus, 2 moles of sulfur dioxide SO₂ would be produced.
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A white salt containing an unknown metal has the formula MCl and gives a lilac flame during a flame test. the salt could be
NaCl
B:
MgCl
C:
KCl
D:
LiCl
Answer:
C
Explanation:
KCl - the flame test for Potassium produces a lilac flame
The metal in the salt has been potassium, and the salt has been KCl. Thus, option C is correct.
The flame test has been performed with the burning of the salt under the flame. The electrons of the elements after gaining the energy have been excited to the higher energy level.
There has been the returning of the electrons to the ground state. In the process. the absorbed energy has been released in the form of visible radiations. The determination of the radiations results in the determination of the metal, as each metal has a unique flame.
The burning of the salt results in the lilac flame. The flame has resembled the burning of potassium. Thus, the metal in the salt has been potassium, and the salt has been KCl. Thus, option C is correct.
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