Iron, an element with the chemical symbol Fe, is an important element. It is used to make steel and is part of the substance that transports oxygen throughout the human body.

Which statement about Fe is supported by the modern atomic theory but not John Dalton’s theory?
A. The element iron is composed of small particles called atoms.
B. The electrons of iron have probable locations in a region of space around the nucleus.
C. Iron atoms combine with other atoms in whole number ratios to form compounds.
D. Chemical reactions that involve iron do not create new atoms of iron.

Answers

Answer 1

Answer:

i think its B

Explanation:

Answer 2

Answer:

aaaaaaaaa

Explanation:


Related Questions

The boiling point of propanoic acid is higher than that of 1-butanol because:

Answers

Explanation:

The boiling point of propanoic acid is higher than that of 1-butanol due to the prevalence of hydrogen bonding in propanoic acid.

Hydrogen bond forms as a result of the electrostatic attraction between the hydrogen of one molecule and a more electronegative specie on another molecule(N or O or F). In propanoic acid, the hydrogen bonding is more pronounced and strong. For 1-butanol, the bonding is weak and not strong.


2)
The amount of energy required to remove all the valence electrons from a cesium atom is
A)
944 kJ/mol
B)
376 kJ/mol
C)
520 kJ/mol
D)
238 kJ/mol

Answers

Answer:

c 520kj mol

Explanation:

times all the electrons

Johnny has thrown a 2kg ball. The ball has an acceleration of 20m/s2. How much was the force that Johnny used?

Answers

Answer:

The answer is 40 N

Explanation:

The force acting on an object given it's mass and acceleration can be found by using the formula

force = mass × acceleration

From the question we have

force = 2 × 20

We have the final answer as

40 N

Hope this helps you

Answer: 40N

Explanation:  

Force = mass × acceleration

20 x 2 = force

20 x 2 is 40

Answer 40 N

NOT 40J

Which of the following molecules has a covalent bond?
A) H-F
B) H-Cl
C) H-Br

Answers

what is the options but i would say A but not sure
All of them are covalent bonds, all the elements are non metals and covalent bonds are formed between 2 non metals.

Consider the reaction: 3Co2+(aq) + 6NO3¯(aq) + 6Na+(aq) + 2PO43¯(aq) â Co3(PO4)2(s) + 6Na+(aq) + 6NO3¯(aq) Identify the net ionic equation for this reaction.A. 3CO2(aq) + 6NO3(aq) + 6Na+(aq) + 2PO43-(aq) â Co3(PO4)2(s) + 6NaNO3(aq). B. Na+(aq) + NO3-(aq) â NaNO3(aq).C. 3CO2(aq) + NO3(aq) + Na*(aq) + 2PO43-(aq) â Co3(PO4)2(s) + NaNO3(aq).D. 3C02(aq) + 2PO43-(ag) â CO3(PO4)2(s).E. None of these choices are correct.

Answers

Answer:

D. 3 Co²⁺(aq) + 2 PO₄³⁻(aq) ⇒ Co₃(PO₄)₂(s)

Explanation:

The complete ionic equation includes all the ions and the insoluble species. Let's consider the following complete ionic equation.

3 Co²⁺(aq) + 6 NO₃⁻(aq) + 6 Na⁺(aq) + 2 PO₄³⁻(aq) ⇒ Co₃(PO₄)₂(s) + 6 Na⁺(aq) + 6 NO₃⁻(aq)

The net ionic equation includes only the ions that participate in the reaction (not spectator ions) and the insoluble species. The corresponding net ionic equation is:

3 Co²⁺(aq) + 2 PO₄³⁻(aq) ⇒ Co₃(PO₄)₂(s)

During winter, you can sometimes ice skate outdoors on a frozen lake. Why can’t you ice skate on a lake when it is not frozen?

Answers

Answer:

Generally the ice should be more than 4 inches thick to skate on it safely. However, the ice thickness is not always even and there can be thin spots, especially near springs or near river inlets or outlets. Most lakes and ponds don't completely freeze because the ice (and eventually snow) on the surface acts to insulate the water below. Our winters aren't long or cold enough to completely freeze most local water bodies. This process of lakes turning over is critically important to the life in the lake.

Explanation:

When the lake it’s frozen, it’s usually a liquid. So you’d probably sink

If the mass of a sample of Mg is 0.500 g and is placed in 100.0 g of HCl, the heat gained is 546.5 J. What is the change in temperature assuming the specific heat of HCl is 4.017 J/K*g?

Answers

Answer:

1.36 K

Explanation:

We have the following data:

The heat gained by HCl is calculated as:

heat = m x Sh x ΔT

where m is the mass of HCl (100.0 g), Sh is the specific heat of HCl (4.017 J/K.g) and ΔT is the change in temperature. We introduce the data in the mathematical expression to calculate ΔT as follows:

ΔT = heat/(m x Sh) = 546.5 J/(100.0 g x 4.017 J/K.g) = 1.36 K

Therefore, the change in temperature is 1.36 K.

2.) Given that the reaction below is a precipitation reaction, what is the missing symbol?
AND
3.) Which of the following would produce a precipitate when mixed water (H20)?

PLZ HELP IM GONNA FAIL THE SEMESTER!!!! I'LL AWARD BRAINLIEST!!

Answers

Answer:

2) (s)

3) PbBr2

Explanation:

2) This is a precipitation rxn which means if forms a solid, We use (s) for solid.

3) Refer to solubility table

Select all possible answers:
Which statement(s) are true about valence electrons?
a. Atoms are very reactive when they have full valence energy levels.
b. Atoms readily lose or gain valence electrons in order to achieve a full
outer energy level.
c. Atoms are stable when they have as many valence electrons as possible.
d. Valence electrons determine many of the properties of an atom.

Answers

Answer:

c and d are correct

Explanation:

In A, false because in Valence Electrons, the more the valences, the more stable an atom is.

In B, false because atoms cannot readily gain or lose valence electrons as the number of valence electrons is determined by the column they are in.

In C, true because the more the valence electrons, the more the stability of an atom.  

In D, true as electron placing is important and the reactivity of an atom is important.

So C and D are true!

The statement(s) which are true about valence electrons are:

c. Atoms are stable when they have as many valence electrons as possible.

d. Valence electrons determine many of the properties of an atom.

An atom refers to the smallest, indivisible unit that isnmade up of matter and forms all chemical elements.

In Chemistry, an atom comprises three (3) distinct particles and these are;

Protons. Neutrons. Electrons.

Valence electrons is simply the number of electrons that is/are present in the outermost shell of the atom of a chemical element.

Generally, valence electrons are typically used to determine whether an atom or group of chemical elements can bond with other chemical elements.

As a general rule, atoms with as many valence electrons as possible are more stable and reaches an octet state.

Lastly, valence electrons are used to determine the chemical properties of of the atom of a chemical element.

Read more: https://brainly.com/question/18214726

In some places, timber companies remove all the trees from entire hillsides when they are
harvesting logs, and farmers till the soil in the fall and leave the ground bare of plants until it is
time to plant in spring. What is the most likely effect of doing either of these things?
A
A. Plants will sprout better.
B. Erosion will happen faster.
C. Soil will stay cooler.
D. Decomposition will speed up.

Answers

Answer:

c

Explanation:

soil will stay cooler

Which one is bigger proton or atom

Answers

Proton is bigger than an atom
Answer:

Aroma are bigger than protons.
Protons are smaller than atoms.

Explanation:

Inside a nucleus are neutrons and protons, which occupy a space about 100,000 times smaller than the whole atom.

A hydrogen atom is 100,000 times bigger than the proton that sits in the middle of it!

A student is using colored beads to model 1 molecule of LaTeX: Ca_3\left(PO_4\right)_2C a 3 ( P O 4 ) 2. The student uses blue beads to model Calcium, red beads to model Phosporus, and green beads to model Oxygen. How many of each color will the student need to make their model?

Answers

Answer:

3 blue beads

1 red beads

4 green beads

Explanation:

The compound given:

               Ca₃PO₄

Elements in the compound are:

Ca

P

O

  Number of atoms are :

Ca - 3

P - 1

O  - 4

blue beads to model Calcium

red beads to model Phosphorus

green beads to model Oxygen

    3 blue beads

    1 red beads

   4 green beads

The freezing point of a solution the freezing point of the pure solvent

Answers

Answer:

This means that a solution must be cooled to a lower temperature than the pure solvent in order for freezing to occur.

Explanation:

Answer:

Freezing Point Depression. The freezing point of a solution is less than the freezing point of the pure solvent. This means that a solution must be cooled to a lower temperature than the pure solvent in order for freezing to occur

Suppose 0.363 g of barium acetate is dissolved in 100. mL of a 25.0 m M aqueous solution of ammonium sulfate. Calculate the final molarity of barium cation in the solution. You can assume the volume of the solution doesn't change when the barium acetate is dissolved in it. Be sure your answer has the correct number of significant digits.

Answers

Answer:

Molarity of Ba²⁺ is 0M

Explanation:

Some barium ion, Ba²⁺ is produced when barium acetate is dissolved (Moles of barium acetate = moles of Ba²⁺ in solution). Then, Ba²⁺ reacts with sulfate ion to produce BaSO₄, an insoluble salt. The concentration of Ba²⁺ is the initial concentration - the concentration of SO₄²⁻ in solution.

Initial moles of Ba²⁺:

Moles barium acetate (Molar mass: 255.43g/mol)

0.363g * (1mol / 255.43) = 1.421x10⁻³ moles of Ba²⁺

Moles SO₄²⁻ = Moles of ammonium sulfate:

100mL = 0.100L * (0.025mol / L) = 2.5x10⁻³ moles of SO₄²⁻.

As moles of SO₄²⁻ are higher than moles of Ba²⁺, Molarity of Ba²⁺ is 0M because all moles of Ba²⁺ reacts producing BaSO₄(s), an insoluble salt.

Describe the relationship between predator and prey in a balanced ecosystem

Answers

Answer:

The predator-prey relationship helps to hold the populations of the two species in equilibrium. ... If the population of prey increases, there is more food for predators. So after a slight period, the predator population is also increasing. If the number of predators increases, more prey is captured.

Explanation:

Answer:

i eat you, you die

Explanation:

thats how life works

Unit Test Unit Test Active 13 TIME REMAINING 01:31:26 Chemical A and Chemical B react in an exothermic reaction. What can be known about what will happen when Chemical A and Chemical B are mixed together? O The new substance will need more energy to form its chemical bonds than the old substance will release. More energy will be released from the old substance than the new substance will need to form its chemical bonds. The color will change as a result of the reaction. O The substance will bubble as a result of the reaction. Save and Exit Next Submit Mark this and return​

Answers

Answer:

More energy is released from the old substance than the new substance needs to form its chemical bonds

Explanation:

Chemical A and Chemical B react in an exothermic reaction. When Chemical A and Chemical B are mixed together more energy will be released from the old substance than the new substance will need to form its chemical bonds. Therefore, option B is correct.

What is an exothermic reaction ?

When a chemical reaction goes on, energy is shifted to or from the surroundings. When energy is moved to the surroundings, this is called an exothermic reaction, and the temperature of the surroundings increases.

Examples of exothermic reactions are combustion reactions and many oxidation reactions.

A chemical reaction is exothermic if heat is passed by the system into the surroundings. Because the surroundings are deriving heat from the system, the temperature of the surroundings increases.

Thus, option B is correct.

To learn more about the exothermic reaction, follow the link;

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#SPJ6

Write the expression for the equilibrium constant Kp for the following reaction. (Enclose pressures in parentheses and do NOT write the chemical formula as a subscript. For example, enter (PNH3)2 as (P NH3)2. If either the numerator or denominator is 1, please enter 1.) PCl5(g) ↔ PCl3(g) Cl2(g)

Answers

Answer and Explanation:

For the following balanced reaction:

PCl₅(g) ↔ PCl₃(g) + Cl₂(g)

We can see that all reactants and products are gases, so it is an homogeneous equilibrium. The expression for the equilibrium constant Kp can be written from the partial pressures (P) of reactants and products as follows:

[tex]Kp=\frac{(P PCl_{3})(P Cl_{2})}{(P PCl_{5})}[/tex]

Where PPCl₃ is the partial pressure of PCl₃ (reactant), PCl₂ is the partial pressure of Cl₂ (reactant) and PPCl₅ is the partial pressure of PCl₅ (product).

Some organizations are buying sections of forest. Once purchased, these sections will never be cut down. What is most likely the main reason for protecting these sections of forest? A Cause the extinction of undesirable animal species, B Prevent these trees from reproducing too fast, C Maintain the diversity of the living environment. D Crovide more land for agricultural purposes.​

Answers

Answer:

I think is C

Explanation:

'Cause the questions says "these sections will Never cut down", so that means is proctecting the environment

SEP Develop Models Each helium atom has two protons. Sketch models
of helium-3 and helium-4, which have approximate masses of 3 amu
and 4 amu, respectively. Label and differentiate protons, neutrons, and
electrons in your models?

Answers

Protons and neutrons are located in the nucleus of the atom while the electrons move in the trajectory of the shell

Further explanation  

Isotopes are atoms whose no-atom has the same number of protons while still having a different number of neutrons.  

So Isotopes are elements that have the same Atomic Number (Proton)  

Isotopes of Helium : helium-3 and helium-4

₂³He :

protons = 2

electrons=protons=2

neutron=mass number-atomic number=3-2=1

₂³He :

protons = 2

electrons=protons=2

neutron=mass number-atomic number=3-2=1

₂⁴He

protons = 2

electrons=protons=2

neutron=mass number-atomic number=4-2=2

Protons and neutron in the nucleus, electrons in the shell

Identify the necessary parts to build a calorimeter. Select one or more:________ A. Cover. B. An interior paper cup. C. Thermometer. D. An interior styrofoam cup. E. An exterior paper cup An exterior styrofoam cup Conductivity probe.

Answers

Answer:

Explanation:

A calorimeter is an instrument used for measuring the heat of reactions and heat capacity. A calorimeter should contain an insulating cover, a thermometer, styrofoam cups (you could have that both on the inside and the outside in the case of a styrofoam calorimeter) and you could also have a conductivity probe (in the form of ignition wires and bulb).

A calorimeter is the analytical device used to measure the heat of the reaction. The construction of calorimeter requires cover, paper cup, thermometer, styrofoam cup, and conductivity probe.

How to build a calorimeter?

In a chemical reaction, the amount of heat released or absorbed by the reaction helps in the analysis of various parameters. The calorimeter measures the heat of the reaction.

The construction of a calorimeter requires:

Paper can for  the filling of water.Cover to stop the loss of heatStyrofoam cup to allow the reactionThermometer to measure the change in temperatureConductivity probe to allow the transfer of heat energy

Learn more about calorimeter, here:

https://brainly.com/question/14989357

This is a Periodic Pun! A cool dude might exclaim this in response to a perfect test score

Answers

Answer:

???

Explanation:

not really sure lol

Which classes of isomers are easier to separate from each other in the laboratory: enantiomers or diastereomers?

Answers

Answer:

diastereomers

Explanation:

Enantiomers are optical isomers that are mirror images of each other. Enantiomers can not be separated by physical methods because the both compounds have almost the same physical properties such as melting points, boiling points, etc. This makes it difficult to separate enanatiomers by conventional methods.

A common method of separating enantiomers is by converting them into diasteromers which are easily separated since diasteromers often have different chemical and physical properties.

Balance the reaction below using the correct coefficient.

__Ag2S --> __Ag + __S8

Answers

Answer:

8Ag2S--->16Ag+S8

Explanation:

thats your answer hope it helps

When water boils, it pushes upward against the air pressure pushing down on it. If there is less air pressure, how does that affect the pooling point ?

Answers

It’s affects it because it basically pushes up the water pressure from h2o to h3o

how could you tell what element it is if only a model was present?​

Answers

You can look at the number of valence electrons and look at the size of the molecule itself to determine which element in this certain group is shown on the model.
the number of valence electrons and the number of molecules

In ionic bonding, atoms__.
A. share electrons
B. are connected by strong electrical forces
C. lose protons and form ions
D. stop moving completely

Answers

In ionic bonding, atoms SHARE ELECTRONS

In frequency modulation, which wave property remains constant?

Answers

Answer:

The correct answer is - Amplitude.

Explanation:

Frequency modulation is a method or procedure that sends or transmits the signals such as radio broadcasting, telecommunication where the value of the transmitted signal is provided by the frequency of a high-frequency wave that carries the signal.

In this method of encoding the information, the amplitude of the carrier remains the same or constant but frequency varies in accordance with the modulating signal.

Answer:

The answer is C Amplitude

Explanation:

Because you can give me Brainiest  PLZZZZZZZZZZZZZZZZZZZZ

How many atoms are in this given equation 6Mn3C2

Answers

Answer:

There are three atoms in the equation

How many moles are in a balloon that is 50.2L, 755 mmHg and -22.0C?

Answers

Answer:

n ≈ 2.42 moles

General Formulas and Concepts:

Chem

Ideal Gas Law: PV = nRT

P is pressure in mmHgV is volume in litersn is number of molesR is a constant (62.4 L · mmHg/mol · k)T is temperature in Kelvins

K = °C + 273

Explanation:

Step 1: Define

V = 50.2 L

P = 755 mmHg

T = -22.0°C = 251 K

Step 2: Find moles n

(755 mmHg)(50.2 L) = n(62.4 L · mmHg/mol · k)(251 K)

37901 mmHg · L = n(15662.4 L · mmHg/mol)

n = 2.41987 moles

Step 3: Check

We are given 3 sig figs. Follow sig fig rules.

2.41987 moles ≈ 2.42 moles

Which descriptions are true regarding different muscle types? Select four options.
Cardiac and skeletal muscles are striated.
Skeletal and smooth muscles are nonstriated.
Smooth and cardiac muscles are voluntary.
Heart and digestive muscles are involuntary muscles.
Smooth and skeletal muscles are involved in movement.
Cardiac muscles work to pump blood.

Answers

Answer:

1, 4, 5, 6

Explanation:

Answer:

1,4,5,6

Explanation:

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