Who was the first person to introduce the concept of atomic mass?

Answers

Answer 1
John dalton is the answer

Related Questions

please help I attached an image

Answers

Answer:

B

Explanation:

Nonmetals have nearly full valence shells and try very hard to get that last few electrons to complete their valence shell. This allows them to achieve noble gas stability. This is why they have high electronegativities and electron affinities.

Nicole pushes her bike up a hill. Overhead, the sun exerts a gravitational force on Earth. Which statement is true about the bike and Earth?

They both experience contact forces.
They both experience non-contact forces.
The bike experiences a non-contact force and Earth experiences a contact force.
The bike experiences a contact force and Earth experiences a non-contact force.

Answers

Answer: c

Explanation:

How do the atoms aluminum and fluorine react to form the compound aluminum fluoride?

Answers

Answer:

Aluminum fluoride is an ionic compound. Meaning that the two elements form a ionic bond. In ionic bonding, atoms receive and donate electrons in order to become stable. In this case, aluminum donates its three outer electrons to three fluorine atoms. Aluminum forms a triple positive aluminium ion (Becomes a cation) and fluorine forms three single negative fluoride ions (Becomes a anion).

Aluminum (3+)Fluorine (1-)

11. If a hypothetical element consisted of three isotopes in the following relative abundance, what would the atomic
mass of the element be?
30.00% 30.00 amu
50.00% 32.00 amu
20.00% 35.00 amu

A. 33.00 amu
B. 32.25 amu
C. 32.00 amu
D. 31.50 amu
E. 31.00 amu

Answers

Answer:

hiroghlipical

Explanation:

new word i just made

what kind of molecule is a polymer??

Answers

polymer is a plastic

Answer:

macromolecules

Explanation:

Polymer is composed of molecules called macromolecules that have multiple of simpler chemical units called monomers.

Which is one factor that adds to the greenhouse effect?

a decrease in the amount of dust in the atmosphere
a decrease in the amount of water on Earth’s surface
an increase in gases in the atmosphere that absorb heat
an increase in the amount of solar radiation that reflects into space

Answers

Answer:

C

Explanation:

Edge 2022 trust the process

Knowing about the greenhouse effect we have that what intensifies this effect is an increase in gases in the atmosphere that absorb heat.

What is the greenhouse effect?

Greenhouse effect is a natural atmospheric phenomenon responsible for the maintenance of life on Earth. Without the presence of this phenomenon, the temperature on Earth would be very low, around -18ºC, which would make the development of living beings impossible.

Thus, the main cause of the greenhouse effect is industrialization. Due to this process, the burning of fossil fuels has intensified in recent centuries. The main products of the combustion reaction of these reagents are the gases mentioned above as the main ones for the greenhouse effect.

See more about greenhouse effect at brainly.com/question/1577730

2. Calculate the heat of combustion of C6H14(l) in kJ/mol if 1.66 g of C6H14(l) were ignited in a calorimeter containing 2750. g H2O. A 3.54˚C temperature rise was observed. The calorimeter constant is 11.2 kJ/˚C. The specific heat of water is 4.184 J/g˚C.

Answers

This problem is describing the combustion experiment where by the heat of combustion of 1.66 g of liquid C6H14 can be calculated via calorimetry. The calorimeter (C=11.2kJ/°C) contains 2750. grams of water with a temperature rise of 3.54 °C, it means we can calculate the total heat released by the combustion of this hydrocarbon via:

[tex]Q_{combustion}=-(Q_{calorimeter}+Q_{water})[/tex]

Because the heat of combustion is released to the water and the calorimeter. Next, we break down each heat and subsequently plug in the given values:

[tex]Q_{combustion}=-(11200\frac{J}{\°C}*3.54\°C +2750.g*4.184\frac{J}{g\°C}*3.54\°C )\\\\Q_{combustion}=-80,379J=-80.4kJ[/tex]

After that, we calculate the moles of C6H14 by considering the given mass and its molar mass (86.18 g/mol):

[tex]n=1.66g*\frac{1mol}{86.18g} =0.01926mol[/tex]

And finally, we divide the total heat of combistion by the moles to get the heat of combustion:

[tex]\Delta H_{comb}=\frac{-80.4kJ}{0.01926mol} =4,174\frac{kJ}{mol}[/tex]

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https://brainly.com/question/14317568https://brainly.com/question/14154214

The difference between Physical/Chemical properties and Physical/Chemical changes

Answers

Physical changes can be reversed and chemical changes can’t be reversed. A physical property is a characteristic which can be identified without changing the substance but to identify a chemical property, you do have to change the substance.

Physical changes can be reversed and chemical changes can’t be reversed. A physical property is a characteristic which can be identified without changing the substance but to identify a chemical property, you do have to change the substance.

omg y'all pls so much help me!!!
1. H2SO4
2. MGNO3
their %​

Answers

H2SO4
H: 1 x 2 = 2
S: 32 x 1 = 32
O: 16 x 4 = 64
98amu

H: 2/98 x 100 = 2%
S: 32/98 x 100 = 33%
O: 64/98 x 100 = 65%


MGNO3 (I think you meant Mg(NO3)2 aka Magnesium Nitrate. So this might be wrong because I did the version you sent instead of what I thought you might mean.)

Mg: 24 x 1 = 24
N: 14 x 1 = 14
O: 16 x 3 = 48
86amu

Mg: 24/86 x 100 = 28%
N: 14/86 x 100 = 16%
O: 48/86 x 100 = 56%


How much heat is required for 10 g of steam specific heat
capacity = 2.01 J/gºC) at 120°C to be heated to 160°C?

Answers

Answer:

145°C is allowed

Explanation:

step step by step explanation

The height that mercury reaches in the tube of a manometer ................on the diameter of the tube.

Answers

Answer:

does not depend

Explanation:

Answer:

DO NOT DEPENDED

Explanation:

I hope it's help u

11.Three atoms of element X react with an element(s) Y from group VIA. What
would be the chemical formula between X and Y.

Answers

Element “X” belongs to family 2A, meaning it is part of the family that includes elements such as Be and Mg. These elements will all have 2 valence electrons and can be represented by the following Lewis diagram:

Element “Y” belongs to family 5A, meaning it is part of the family of elements that includes elements such as N and P. These elements will all have 5 valence electrons and can be represented by the following Lewis diagram:

Atoms from these two families will usually react with each other by losing or gaining valence electrons to create stable ions (an ion is what we call an atom/particle that has a charge). These stable ions form by the atoms either losing or gaining electrons until they have the same number of valence electrons as the nearest Noble Gas. This means that each ion will have a full valence shell (usually consisting of 8 electrons), often referred to as a “stable octet”, and this process of creating stable ions is often called the “octet rule”.

Atoms with fewer that 4 valence electrons will normally have a weak hold on their valence electrons and will tend to lose their valence electrons when forming ions.

Atoms with 4 or more valence electrons will normally have a strong hold on their valence electrons and will tend to gain electrons when forming ions.

The charge on the ion arises from the fact that, initially, the atom is electrically neutral because it has the same number of electrons (negative charges) as protons (positive charges). By losing electrons, the atom will end up with more protons (positive charges) than electrons (negative charges) and will form an ion with an overall positive charge. By gaining electrons, the atom will end up with more negative electrons than positive protons becoming an ion with an overall negative charge.

So, an atom of element “X”, with only 2 valence electrons, must lose its 2 valence electrons (which will be gained by element “Y”) to form a stable ion with a 2+ charge (losing two electrons leaves the ion with 2 more positive charges (protons) than negative charges, so a net charge of 2+).

An atom of element “Y”, with 5 valence electrons, must gain 3 electrons (from element “X”) to form a stable ion with a 3- charge (gains 3 extra negative charges).

We can show this process using Lewis diagrams:

From this set of diagrams you can see that in order to create stable ions of both “X” and “Y” we need these atoms to react with each other in a 3:2 ratio (we need 3 atoms of X for every 2 atoms of Y). This means that the resulting chemical formula of the compound will be:

Now, we will look at a short cut that can help you figure this out without having to draw Lewis diagrams.

Compounds are electrically neutral, meaning they must contain equal numbers of positive and negative charges. For compounds consisting of oppositely charged ions, this means that the total charge of the negative ions must be equal to the total charge of the positive ions. In other words the ions must combine in a ratio that makes their charges add to zero.

If we look at the compound we just made, X3Y2, we can confirm this:

So, now you can you predict the formula of simple ionic compounds:

from the family of elements, determine the number of valence electrons each element has

determine the charge of the ions that each atom will form using the octet rule (or look on the periodic table, most will tell you the stable ionic charges that each element can form)

determine the ratio of positive ions to negative ions that results in an overall charge of zero

Example,

What is the formula of a compound produced when an element from family 3A combines with an element from family 7A?

What would be the bond angle if the molecular geometry were bent and had only one lone pair of electrons

Answers

120°

Bent molecular geometry

Examples H2O, SO2

Point group C2v

Coordination number 2

Bond angle(s) 90°<θ<120°

I need help with this question

Answers

It would be 4-ethyldecane. It has 12 carbons.

Is the partial pressure of o2 higher in water or the air?

Answers

Since inspired air is 21% oxygen and atmospheric pressure is 760 mmHg (at sea level), the partial pressure of oxygen is 0.21 x 760 mmHg = 160 mmHg. As air moves into the alveoli, water vapor and carbon dioxide are added, and that reduces the partial pressure of oxygen to about 100 mmHg in the alveolar gas.

2KClO3 —> 2KCl + 302 this equation represents both a ___ reaction AND a(n) ___ reaction.

A. combustion; decomposition
B. single replacement; combustion
C. combustion; oxidation-reduction
D. decomposition; oxidation-reduction

Answers

Answer:

option D--Decomposition; oxidation-reduction

Answer: A. Combustion; decomposition

Explanation: I took it on a quiz and got it right!

How do scientists analyze the TRAPPIST system?

Answers

Answer:

A team led by Michaël Gillon at the University of Liège in Belgium detected the planets using transit photometry with the Transiting Planets and Planetesimals Small Telescope (TRAPPIST) at the La Silla Observatory in Chile and the Observatoire de l'Oukaïmeden in Morocco.

Explanation:

This is just how the TRAPPIST system was discovered.

Here's the link about the information you need:

https://www.nasa.gov/press-release/nasa-telescope-reveals-largest-batch-of-earth-size-habitable-zone-planets-around

Indique cuáles son las unidades de la molaridad *
eq-g/m³
eq-g/L
mol/cm³
mol/L

Answers

Answer:

hm

Explanation:

Blood has a mass-volume percent of NaCl of 0.9%. What mass (g) of NaCl is present in a liter of blood

Answers

The mass (g) of NaCl that is present in a liter of blood is 0.347g.

HOW TO CALCULATE MASS:

The mass of a substance can be calculated by multiplying the decimal mass-volume of the substance by its molar mass.

According to this question, Blood has a mass-volume percent of NaCl of 0.9%. This means that 0.9/100 = 0.009g of NaCl is present in each 100g of blood.

Molar mass of NaCl = 23 + 35.5 = 38.5g/mol

Mass of NaCl in a liter of blood = 38.5 × 0.009

Mass of NaCl in a liter of blood = 0.347g of NaCl.

Therefore, The mass (g) of NaCl that is present in a liter of blood is 0.347g.

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Are bath bombs pure substances or mixtures

Answers

Answer:

Yes.

Explanation:

Bath bombs are usually made from three key ingredients: baking soda, citric acid and cornstarch, said Frankie Wood-Black, an instructor in chemistry at Northern Oklahoma College and an experienced bath-bomb maker. Often, bath bombs also include dyes and perfumes, and sometimes they have epsom salt.

Answer: yes

Explanation:

Holding a marshmallow near a campfire flame causes it to turn brown even if the marshmallow does not touch the flame. Why does this happen?
A.
Dust blowing through the air causes the marshmallow to brown.
B.
Hot air in the atmosphere cooks the marshmallow.
C.
Heat radiates from the fire and cooks the marshmallow.
D.
Smoke and soot from the fire cause the marshmallow to brown.

Answers

Answer:

The answer is, C. Heat radiates from the fire and cooks the marshmallow.

Answer:

C Heat radiates from the fire and cooks the marshmallow.

Explanation:

Heat can be transferred through space through the process of radiation. The marshmallow is toasted because heat radiates from the fire and cooks the marshmallow.

A significant amount of methane (CH4) is trapped underground or under marine sediments as Select one: a. methane hydrates. b. liquid methane. c. inorganic carbon. d. natural gas.

Answers

Methane is found under the ground or under marine sediments  as natural gas which is mined along with crude oil.

Methane is an alkane and has the formula CH4. It is most commonly used as fuel. Methane is the gas that has been renowned as being responsible for explosion in coal mines.

Methane is found under the ground as natural gas which is mined along with crude oil. Large deposit of natural gas is found in many countries in Asia, Africa and the middle east.

Learn more: https://brainly.com/question/6505878

if the student finds the weight of the sodium chloride to be 28.5g,calculate the number of particles.(Na=23,Cl=35.5)

Answers

Answer:

2.93×10^23

Explanation:

molecular formula of NaCl is 58.5

58.5gof NaCl=6.023×10^23

28.5g of NaCl= 6.023×10^23÷58.5×28.5

= 2.93×10^23

What list only includes physical properties

Answers

[tex] \large \text{Answer} \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ [/tex]

Boiling points,conductivity and colours contain only physical properties

Physical properties can include qualitative and quantitative observations. Which can be any measurements, changes of state, colour, smell, mass, shape, texture, malleability and ductility.

The same quantity of each solute is added to water. Which solution will have the greatest number of H30+ ions at equilibrium?
(1 point)
O weak acid
O strong acid
O strong base
O weak base

Answers

Answer is strong acid

According to Dalton, atoms cannot be SELECT ALL THAT APPLY a Created b Destroyed c Subdivided d Bonded​

Answers

Answer:

The answer is subdivided,created or destroyed

What is mechanical energy?

The energy that is associated with the motion or position of an object
The energy that travels in waves from the moon
Any energy that travels through a medium like water
The stored energy in a substance like oil or gasoline

Answers

Answer:

The energy that is associated with the motion or position of an object

or simply kinetic or potential Energy

The pathogen below is a single-celled organism without a nucleus that can cause illness in a humans.

Answers

Answer:

bacteria

Explanation:

The pathogen below is a single-celled organism without a nucleus that can cause illness in a humans.

If an organic compound has a carbonyl group and a hydroxyl group, with the carbonyl group connected to two R groups, is it considered an alcohol or a ketone? Or can it have properties of both?

Answers

Answer:

A carboxyl group (COOH) is a functional group consisting of a carbonyl group (C=O) with a hydroxyl group (O-H) attached to the same carbon atom. Carboxyl groups have the formula -C(=O)OH, usually written as -COOH or CO2H.

I NEED HELP
so is for example
FeO + H2O ---> Fe(OH)2
And
Fe + 2H20 ---> Fe(OH)2 + H2
The same? Same thing for other metals

Answers

Answer:

no

Explanation:

because when is iron oxide + water given you iron hydroxide while the other one is Iron plus 2 moles of water giving you iron hydroxide and hydrogen

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