an atomic mass unit is defined exactly as

Answers

Answer 1

Answer:Atomic mass is the mass of an atom in atomic mass units (amu)

Atomic mass

• atomic mass (sometimes called atomic weight) is the mass of the atom in atomic mass units (amu). (from periodic table)

o One atomic mass unit is defined as a mass exactly equal to one-twelfth the mass of one carbon-12 atom. Carbon-12 is the carbon isotope that has six protons and six neutrons. Setting the atomic mass of carbon-12 at 12 amu provides the standard for measuring the atomic mass of the other elements.

o For example, experiments have shown that, on average, a hydrogen atom


Related Questions


The density of air at STP is 1.285 g/L. Which of the following cannot be used to fill a balloon that will float in air at STP?

Answers

NO can't  be used to fill a balloon

Further explanation

Conditions at T 0 ° C and P 1 atm are stated by STP (Standard Temperature and Pressure). At STP, Vm is 22.4 liters/mol.

Answer options that need to be added :

a. Ne

b. NO

c. NH₃

d. CH₄

e. HF

will float in air ⇒ element or compound to fill the balloon, its density must be less than < 1.285 g/L

We can use the ideal gas formula ta find density :

[tex]\tt \rho=\dfrac{P.MW}{RT}[/tex]

Because at STP, then the constant value is

[tex]\tt \rho=\dfrac{1~atm\times MW}{0.08205\times 273.15~K}\\\\\rho=0.0446\times MW[/tex]

So that the density is determined from the MW(molecular weight) of each element or compound

a. Ne

Ar = 20.1797 g/mol

[tex]\tt \rho=0.0446\times 20.1797=0.9~g/L[/tex]

b. NO

MW=30.006 g/mol

[tex]\tt \rho=0.0446\times 30.006=\boxed{\bold{1.338~g/L}}[/tex]

c. NH₃

MW=17.0306 g/mol

[tex]\tt \rho=0.0446\times 17.0306=0.760~g/L[/tex]

d. CH₄

MW=16.04 g/mol

[tex]\tt \rho=0.0446\times 16.04=0.715~g/L[/tex]

e. HF

MW=20.01 g/mol

[tex]\tt \rho=0.0446\times 20.01=0.892~g/L[/tex]

What is the correct name for the compound P406?
A. Phosphoric acid
B. Tetraphosphorus hexoxide
C. Phosphorus (IV) oxide
D. Phosphorus oxide

Answers

Answer:

Phosphorus trioxide

Explanation:

Answer:

Tetraphosphorus hexoxide

Explanation:

Give brainliest please

why is lithium used in the body?

Answers

Answer:

11

Explanation:

Aquanauts explore the area called?

Answers

Answer:

Inner space

Explanation:

I hope this helps

Convert 122 moles of Methane to liters?

Answers

122 moles of Methane to liters is 2734.5

Which description applies to a physical property? Choose the correct answer
O depends directly on the amount of the substance present
O examines changes in the composition and structure of matter
O measured or observed without changing the identity and composition of matter
O determined by changing the identity of a substance and observing how it reacts

Answers

Answer:

the third one, measured or observed without changing the identity and composition of matter. because physical property does not under go any change but can be put back.

Which of the following is false regarding supersonic speed?

Question 10 options:

When an object reaches supersonic speed a sonic boom will occur.


When an object reaches supersonic speed it is moving faster than the speed of light.


When an object has reaches supersonic speed it breaks the sound barrier.


When an object supersonic speed it is moving faster than 343 meters/second.

Answers

Answer:

the answer is C

Explanation:

i know this one, and may YOU PLEASE MARK BRAINLIEST I ONLY NEED ONE MORE CROWN TO MOVE TO THE NEXT RANK


Which RNA strand would match with this DNA strand?
AGGCTAAT

Answers

What is the DNA strand? You have not named it.

How many neutrons make up one of these potassium atoms?

Answers

Potassium has twenty neutrons

Answer:

20

Explanation:

What is hydrochloride acid plus water plus salt and water

Answers

ANSWER:

It is called Caffeine Hydrochloride.
Formula: HC8H10N4O2Cl

what unit of measure would i use to measure the width of my fingernail A millimeters
B centimeters C meters D kilometers
E grams​

Answers

A. Millimeters
Because the width of fingernails are very small and millimeters is the smallest unit of measurement listed.

Elements in group to are cold alkaline earth metals what is most similar about alkaline earth metals how many protons and neutrons they have which Chemical properties he have how many total electrons they have which period They have most often found in

Answers

Answer:

explanations below

Explanation:

The alkaline earth metals are the 6 chemical elements that can be found in group two of the periodic table. These elements have a lot of properties in common, in the sense that they are generally shiny, reactive at standard temperature and pressure and they are also silvery-white. The elements are beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra)

These metals have two electrons at their orbits, which can be easily lost to form cations (with charge +2, and an oxidation state of +2)  

Below are some of their details

Name: Beryllium  

Number of Protons/Electrons: 4  

Number of Neutrons: 5  

Name: Magnesium  

Number of Protons/Electrons: 12  

Number of Neutrons: 12  

Name: Calcium  

Number of Protons/Electrons: 20  

Number of Neutrons: 20  

Name: Strontium  

Number of Protons/Electrons: 38  

Number of Neutrons: 50  

Name: Barium  

Number of Protons/Electrons: 56  

Number of Neutrons: 81  

Name: Radium  

Number of Protons/Electrons: 88  

Number of Neutrons: 138  

what is 1.23 x 10^-3 in standard notation

Answers

Answer:

=0.00123

Explanation:

Look at the attachments below

Hope this helps (:

Answer:

0.00123

Explanation:

Standard notation is the normal way of writing numbers. Examples include 1, 2, and 10. The number 1.23 x 10^-3 is written in scientific notation. The decimal goes after the first nonzero integer and it is multiplied by a power of 10. The power or exponent attached to the 10 tells you how many places over you need to move the decimal to get back into scientific notation. Examples include 1.00 x 10^2 (representing 100 in standard form because you would move the decimal two places to the right.), 2.0 x 10^1 (representing 20 in standard form because you would move the decimal one place to the right), and 3.0 x 10^-4 (representing 0.0003 in standard form because you would move the decimal four places to the left since it is a negative exponent).

The negative (-3) exponent in 1.23 x 10^-3 indicated to move the decimal three places to the left. If it was positive, you would move it three places to the right.

In 1.23 x 10^-3 move the decimal to the left 1 place to get:

0.123

two places to get:

0.0123

and a third place to get:

0.00123

The final answer is 0.00123

50 POINTS: PLEASE ANSWER AS QUICK AS POSSIBLE!

Question:

After getting their results in, a group of scientists went back and looked at their study. As planned, their experiment consisted of three groups. The first group received a new medicine at a normal dose, the second group received the medicine at half the dose, and the third group received the medicine at twice the dose.

Which of the following best describes what went wrong with the scientists’ study?


Choices:

- an improper experimental procedure

- the lack of a control group

- selection bias

- human error

Answers

Explanation:

The lack of a control group

The answer would be “the lack of a control group.” To make the results more accurate, the scientists should have used a placebo group to use as a comparison.

I need help in chemistry!!!!!!!!!!!

Answers

Answer:

ok whats the question dude just ask :PPPPPPPPPPPPPPPPPPPPPP

OTHERWISE EOEOEEOEOEOOEOEOEOEOEOOEOWOWOWOWOW

wow is mom upide down

Explanation:

This is the answer hope you see it clear :)

A dull metal object has a density of 8.8 G/ML and a volume of 20 ML calculate the mass

Answers

Answer:

Mass = 0.000176 gram

Steps:

m =  V × ρ

=  20 milliliter × 8.8 gram/cubic meter

=  2.0E-5 cubic meter × 8.8 gram/cubic meter

=  0.000176 gram

Explanation:

A metal object has a density of 2 g/ml. When placed in a graduated cylinder with 500 ml of water, the
water rises to 508 ml. What is the mass of the metal object?

Answers

Answer:

The answer is 16 g

Explanation:

The mass of a substance when given the density and volume can be found by using the formula

mass = Density × volume

From the question

density = 2 g/ml

volume = final volume of water - initial volume of water

volume = 508 - 500 = 8 mL

We have

mass = 2 × 8

We have the final answer as

16 g

Hope this helps you

Plowing is an example of what Energy?

a. Kinetic Energy
b. Potencial Energy​

Answers

Answer:

mechanical or kinetic eg hammer and nails

what is ch2cl2 bond angle?

Answers

Answer:

109.5

Explanation:

It's a tetrahedreal with four bonds

Dilute hydrochloric acid reacts with sodium

2HCl(aq) + Na2CO3(aq) + 2NaCl(aq) + H2O(l) + CO2(g)

A Explain why effervescence is seen during the reaction.

Answers

Answer:

Because the reaction releases CO2 gas

Explanation:

therefore creating an effervecence within the solution as the carbonate dissociates

In science class, a student is given a copper cylinder to investigate. The student measures the mass of the cylinder as 53.76 grams. The
student measures the volume of the copper as 6 cm. Which additional property of the copper can the student determine from these
measurements?

Answers

Answer:

From these two values, i.e. mass and volume, density of the copper cylinder can be calculated.

Formula of density is :

Density = Mass / volume.

Now we have mass: 53.76g and volume 6cm³

Density = 53.76 / 6

Density= 8.96 g/cm³

Based on the article "Will the real atomic model please stand up?," describe what Dalton's theory states about a molecule of water. Dalton's theory about compounds tells us that all water molecules have different kinds of atoms, two hydrogen atoms for every one oxygen atom.

Answers

Answer:

Follows are the solution to this question:

Explanation:

The characterization with water molecules would be that light waves are made up of 2 different types of atoms (2 hydrogen and 1 oxygen atoms), as per the Dalton theory. There are many multiple times as many atoms of hydrogen as oxygen atoms in each water molecules. For every two hydrogen atoms, all water molecules have one oxygen atom.

Answer:

Sample Response: Dalton’s theory about compounds tells us that all water molecules have different kinds of atoms, two hydrogen atoms for every one oxygen atom.

Explanation:

What metal is Potassium (K)?

Answers

Explanation:

Potassium is a chemical element with the symbol K and atomic number 19. Potassium is a silvery-white metal that is soft enough to be cut with a knife with little force. Potassium metal reacts rapidly with atmospheric oxygen to form flaky white potassium peroxide in only seconds of exposure

Answer:

alkali metal

Explanation:

Potassium is a chemical element with symbol K and atomic number 19. Classified as an alkali metal

Two compounds of phosphorus and fluorine have the following
mass ratios.
Compound 1: 10.14 g fluorine for every 3.38 g phosphorus
Compound 2: 8.42 g fluorine for every 4.21 g phosphorus
Find the whole number ratio of masses of fluorine in compound
1 to compound 2.

Help me please

Answers

Answer: 3:2

Explanation: (10.14÷3.38)÷(8.42÷4.21)=1.5=3/2

Which further observation led Mendeleev to create the periodic table

Answers

Answer:

Mendeleev realized that the physical and chemical properties of elements were related to their atomic mass in a 'periodic' way, and arranged them so that groups of elements with similar properties fell into vertical columns in his table.

Explanation:

google

Which phrase is most similar in meaning to “scientific theory”?
A. a best guess explanation
B. a rigorously tested explanation
C. an opinion of what should happen
D. a mathematical relationship

Answers

Answer:

c

Explanation:

Answer:

A. a best guess explanation

Explanation:

A scientific theory explains why something behaves the way it does and is usually backed up by different sources. They are not speculations and can be proven. Those which are speculations and are not proven are called hypothesis. A scientific theory can also be replaced, if it is found that it does not produce valid results, or if a better theory is proposed which is made of one or more old theories.

You will learn in this course that organic compounds have covalent bonds with a significant amount of energy stored in them. This is why we burn fossil fuels to generate energy to heat our homes or drive our cars. Given this information, which of the compounds listed below would you expect to have the most energy is its carbon-carbon bond?

Answers

Answer:

See explanation

Explanation:

This question is obviously supposed to be a multiple choice question but the options are missing.

However, the question intends to test the student's knowledge about combustion of fossil fuels. Fossil fuels are mostly composed of hydrocarbons of different chain lengths.

The longer the chain length, the greater the energy released when the compound is burnt since there are more energy stored in its bonds.

Hence, the correct answer to this question will be the option that contains the greatest number of C-C and C-H bonds.

Please answer it correctly and explain clearly

Answers

Answer:

i think that the children will inherit the brown eyes, it is the best answer since the other things cant be inherited and he dyed his hair blonde

Explanation:

How many protons, electrons and neutrons do A nitrogen atom with atomic number 7 and mass number 14

Answers

Answer:

p =7

e = 7

n = 7

Explanation:

proton = atom number

electron = atom number - muatan

neutron = mass nimber - atomic number

what does CER mean for science?

Answers

Explanation:

Claim, Evidence, Reasoning (CER) model, an explanation consists of: A claim that answers the question. Evidence from students' data. Reasoning that involves a rule or scientific principle that describes why the evidence supports the claim.

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