Answer:
2.
63.9 cm2
Explanation:
All non-zero digits are consider significant figures like 1, 2, 3, 4, 5, 6, 7, 8, 9.
Leading zeros are not consider as a significant figures. e.g. 0.06 in this number only one significant figure present which is 6.
Zero between the non zero digits are consider significant like 108 consist of three significant figures.
The zeros at the right side e.g 240000 are also significant. There are six significant figures are present.
When we add or subtract the values the number of significant figures after decimal in result must be equal to the given measurement having less number of decimal places. For example,
The difference between 7.69 and 4.0.
7.69 - 4.0 = 3.7
When we multiply or divide the values the number of significant figures must be equal to the less number of significant figures in given value.
For example in given q:
52.6 cm × 1.214 cm = 63.9 cm²
A substance can change into a new kind of molecule when:
Answer:
Chemical changes cause a substance to change into an entire substance with a new chemical formula. Chemical changes are also known as chemical reactions. The “ingredients” of a reaction are called reactants, and the results are called products.
Hope it helps
Why Hund's Rule is called maximum spin multiplicity rule?
Answer:
The rule states that for a given electron configuration, the lowest energy term is the one with the greatest value of spin multiplicity. This implies that if two or more orbitals of equal energy are available, electrons will occupy them singly before filling them in pair
Explanation:
Round the value 44.981
Answer: 45
Explanation: it would be 45 bc if the value is 5 and over the number goes up and if it is lower than 5 it would stay the same.
Answer:
45 is the answer
Explanation:
2. Ultraviolet radiation has a frequency of 6.8 x 10'5Hz. Calculate the energy, in
joules, of the photon.
Answer:
[tex]E=4.5\times 10^{-18}\ J[/tex]
Explanation:
It is given that, the frequency of Ultraviolet radiation is [tex]6.8\times 10^{15}\ Hz[/tex]
We need to find the energy of the photon. The formula for the energy of a photon is given by :
[tex]E=hf\\\\\text{Where h is Planck's constant}\\\\E=6.63\times 10^{-34}\times 6.8\times 10^{15}\\\\E=4.5\times 10^{-18}\ J[/tex]
So, the energy of the photon is [tex]4.5\times 10^{-18}\ J[/tex].
An ideal sample weighing 1.28g at 127C (temp) and 1 atm has a volume of 0.250L. Determine the molar mass of the gas.
Answer:
Molar mass of gas = 160 g/mol
Explanation:
Given data:
Mass of sample gas = 1.28 g
Temperature of sample gas = 127°C (127+273 = 400K)
Pressure of sample gas = 1 atm
Volume of sample gas = 0.250 L
Molar mass of gas = ?
Solution:
Formula:
PV = nRT
R = general gas constant = 0.0821 atm.L/ mol.K
Now we will put the values in formula.
1 atm × 0.250 L = n × 0.0821 atm.L/ mol.K ×400K
0.250 L.atm = n ×32.84atm.L/ mol
n = 0.250 L.atm/32.84atm.L/ mol
n = 0.008 mol
Molar mass of gas:
Number of moles = Mass/molar mass
0.008 mol = 1.28 g / molar mass
Molar mass = 1.28 g / 0.008 mol
Molar mass = 160 g/mol
What is the ratio of aluminum atoms to oxygen atoms in aluminum oxide?
Answer:
Al2 O3 or 2:3
Explanation:
The aluminum oxide consists of two elements, which are oxygen atoms and aluminum atoms, and there are 2 aluminum atoms and 3 oxygen atoms in aluminum oxide. The ratio from aluminum atoms to oxygen atoms is 2:3.
There are two types of chemical compound one is covalent compound and other is ionic compound, covalent compound formed by sharing of electron and ionic compound formed by complete transfer of electron. Therefore, the ratio of aluminum atoms to oxygen atoms in aluminum oxide is 2:3.
What is chemical Compound?Chemical Compound is a combination of molecule, Molecule forms by combination of element and element forms by combination of atoms in fixed proportion.
An ionic compound is a metal and nonmetal combined compound. Ionic compound are very hard. They have high melting and boiling point because of strong ion bond. The ratio of aluminum atoms to oxygen atoms in aluminum oxide is 2:3. Aluminium oxide is an ionic compound.
Therefore, the ratio of aluminum atoms to oxygen atoms in aluminum oxide is 2:3.
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The half life of radon 222 is 3.824 days, how much time must pass of one fourth of a given amount of radon to remain?
Answer:
After 7.648 days, you will see one quarter.
Explanation:
1 → 0.5 → 0.25
Since half life of radon-222 is 3.824 days, you need twice this time to get one quarter at the end.
2 ⋅ 3.824 = 7.648 days.
I'd is 643461717 and password is dynamo
Answer:bet
Explanation:
if atom X has 6 protons,6 neutrons and 6 electrons and aton Z has 6 protons,7neutrons and 6 electrons,atom x and atom z are isotopes of the element
i need help please!
asap
Answer:
Earth is pulling up on the book with a force of 4n i think
Explanation:
Describe the transmission of sound through solids,liquids,and gases.
I tihink it will help you
Which food molecules are outside of the tube
Answer:
Absorption
Explanation:
I think from Quizlet
How to find the number of atoms?
To find the number of atoms, we multiple the number of mols by Avogadro's number, about 6.02x10^23
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Answer:
to calculate the numbers of atoms in a sample, divide it's weight in grams by the amu atomic mass from the periodic table, then multiply the result by avogadro's number: 6.0 × 10^24
NEED HELP ASAP! BRAINLEST + THANKS!
if three electrons are available to fill three empty 6p atomic orbitals, how will the electrons be distributed in the three orbitals
a.) one electron in each orbital
b.)two electrons in one orbital, one in another, none in third
c.) three in one orbital, one in other two
d.) cannot be predicted, determined by random chance
Answer:
A) one electron in each orbital
Explanation:
Orbitals get electrons one at a time. If there are three electrons and three empty orbitals, then one electron will go into one orbital!
What is the process whereby scientists check each other’s work?
A. defining the audience
B. conferencing
C. peer reviewing
D. writing
Answer:
peer reviewing
Explanation:
Its peer reviewing because there peers and there reviewing eachothers work
The process whereby scientists check each other’s work is peer reviewing.
What is peer group?Peer group are the groups of people of same age, same background with same interest.
In the peer reviewing process group of members will check, evaluate and correct each others work, which in turn help the members of the group to update their work.
Hence, option (c) is correct i.e. peer reviewing is the process whereby scientists check each other’s work.
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Help this is not that hard I think
Answer:
1,) True
2.) False
3.) A Moraine
Explanation:
Hope this helps
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Calculate the volume in milliliters of a 5.05-g sample of a solid with a density of 3.25 g/mL.
Answer:
The answer is 1.55 mLExplanation:
The volume of a substance when given the density and mass can be found by using the formula
[tex]volume = \frac{mass}{density} \\ [/tex]
From the question
mass = 5.05 g
density = 3.25 g/mL
We have
[tex]volume = \frac{5.05}{3.25} \\ = 1.5538461...[/tex]
We have the final answer as
1.55 mLHope this helps you
which of the following is a state of matter ? particle,thermal,plasma, and diffuse ?
Answer:
a particle
Explanation:
matter takes up space, and particles take place in atoms
Answer:
plasma is a state of matter
Kinetic molecular theory states... (choose all that apply)
A. There is a chemical change when a solid melts to a liquid.
B. Particles that make up matter have kinetic energy.
C. Particles that make up matter are always in motion
Convert each of the following masses to the units requested.
a. 0.765g to kilograms
b. 1.34 g to milligrams
c. 34.2mg to grams
Answer:
a) 0.000765kg
b) 1340mg
c) 0.0342g
Explanation:
a) 1000g = 1kg
0.765g= 0.765/ 1000
= 0.000765g
b) 1g = 1000mg
1.34g = 1.34 × 1000
= 1340mg
c) 1000mg = 1g
34.2mg = 34.2/1000
= 0.0342g
Calculate the density of helium if a balloon with a capacity of 5.00 L holds 0.890 g.
Answer:
Explanation:
Density is m/V. Also, 1 liter = 1000 [tex]cm^3[/tex]. So, we get 0.890/(5*1000) = [tex]1.78*10^{-4}[/tex] g/cm^3. You can convert this to kg/m^3 as well by multiplying it by 10. Depends which one you want.
The ratio of the mass in grams and volume in cubic meters gives the density. The density of 0.80 gm helium is 1.78 × 10 ⁻⁴ g/cm³.
What is density?Density is the amount or the number of entities that can be contained in an area. It is denoted by ρ and is calculated as,
Given,
Mass = 0.890 gm
Volume = 5000 cm³
ρ = Mass ÷ Volume
= 0.890 ÷ 5000
= 1.78 × 10 ⁻⁴ g/cm³
Therefore, 1.78 × 10 ⁻⁴ g/cm³ is the density of helium.
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A student has a container of sand and sugar. What characteristic could be used to separate the mixture?
Answer:
Sugar will dissolve, so water.
Explanation:
Sugar is a bicubacle food source you could say, sand will not evaporate or dissolve in the water since it is not a 3c2e source. Using water will seperate them.
Answer: Heat
Explanation:
Because is you put water and sand in a container you can separated by boiling the water and all the water would evaporate and the sand would stay.
All the following are examples of selective breeding EXCEPT a wild dog that finds and mates with a domestic dog. neutering a horse that is particularly small for its breed. adding sheep from another country to the bloodline to help combat disease. purposely mating larger pigs to increase the amount of meat produced.
Answer:
A. a wild dog that finds and mates with a domestic dog.
Explanation:
What information does a subscript in a chemical formula provide? Choose all that apply. * The charge of that atom while in the compound How many of each atom are present in the compound How many valence electrons each element has while in the compound How many valence electrons each element starts with In ionic, the simplified ratio of atoms in relation to each other
Answer:
B. How many of each atom are present in the compound
D. the simplified ratio of atoms in relation to each other
Explanation:
In a chemical formula, chemical elements or atoms are represented by a chemical symbol for example Fe for iron and Na for sodium, and the number of each atom is represented by a subscript such as CO2, where 2 is a subscript representing 2 atoms of oxygen.
A subscript represents the number of each atom in the compound and the simplified ratio of atoms in relation to each other. The simplified ratio of atoms in relation to each other means subscript shows the contribution of both the atoms in the compound, for example: N2 + 3H2 => 2NH3, it means the subscript showing the ratio or proportionate of atoms that is 2:2 for both nitrogen and hydrogen.
The subscript is always written below and to the right of the chemical symbol.
Hence, the correct answer is "B. How many of each atom are present in the compound and D. the simplified ratio of atoms in relation to each other"
where is lithium used in the body?
Answer:
Lithium is a naturally occurring alkali metal, which living organisms ingest from dietary sources and which is also present in trace amounts in the human body. In much higher concentrations, lithium is effective as a medication for mania and mood swings including manic depressive disorders
Students were investigating properties of matter, but wanted to make sure that when they tested these properties they had properties that would represent the matter they were testing specifically. The students claim that they are going to test intrinsic properties. What evidence and reasoning would you provide to justify this claim? (7 points)
Answer:
See explanation
Explanation:
An intrinsic property is a property that is internal, that is, it characterizes the substance under study. The possession of an intrinsic property depends on the nature of the substance. An intrinsic property does not depend on amount of substance but on the nature of the substance.
Examples of intrinsic properties include; Density. Solubility, Melting Point, Freezing Point, Boiling Point, Conductivity etc.
Intrinsic properties really represent the matter that is being studied. For instance, the boiling point of water will always be 100°c. No other liquid can boil exactly at that temperature. Hence, this intrinsic property can always be used to identify an unknown liquid as water.
The students were right, studying intrinsic properties accurately represent the matter that is being studied.
What are some things that uses oxygen
Answer:
Common uses of oxygen include production of steel, plastics and textiles, brazing, welding and cutting of steels and other metals, rocket propellant, oxygen therapy, and life support systems in aircraft, submarines, spaceflight and diving.
While designing his recording studio, Brian was trying to determine what type of surface he should use for his studio walls. He wanted to be able to produce clear, crisp, sound. So he needed a surface that wouldn't cause his music to echo. What type of surface should Brian use for his studio walls?
Answer: Acoustic Foam.
Explanation:
Acoustic Foam: This is a kind of material, which is commonly known as it called a Studio Foam, it has a kind of wedge or pyramid shape that plays a big role in absorbing sound. Brian would have to use acoustic foam by placing them round the walls and ceiling as this would stop any echoing sound and in return give a crisp and clear sound when music is been played it the studio.
How do minerals differ from ores?
Ores: metal/coal (iron, gold, coal)
Mineral: not metal, (Granite, limestone,
What is the density of nitrogen gas if 0.256g occupies a volume of 100mL?
Answer:
The answer is 0.00256 g/mLExplanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\ [/tex]
From the question we have
[tex]density = \frac{0.256}{100} \\ [/tex]
We have the final answer as
0.00256 g/mLHope this helps you