Iron, Fe, is a solid at room temperature. Iron is a shiny, bright white metal that is soft, malleable, ductile and strong. Its surface is usually discolored by corrosion, since it combines readily with the oxygen of the air in the presence of moisture. The density of iron is 7.86 g/cc. Iron is a good conductor of electricity and heat. Consider the paragraph above. What is one chemical property of iron? A) Iron is malleable. B) The density of iron is 7.86 g/cc. C) Iron combines readily with oxygen. D) Iron is a good conductor of electricity and heat.

Trace fossils provide us with indirect evidence of life in the past, such as the footprints, tracks, burrows, borings, and feces left behind by animals, rather than the preserved remains of the body of the actual animal itself. so i would say B.

The option that can be classified as a trace fossil is b.shrimp burrow

A trace fossil is a fossil that contains traces of ancient plants or animals such as footprints, nests, burrows, or excrement in an indirect, visible manner. Ichnology is the field of study of trace fossils.

Body fossils and trace fossils are frequently discovered together in the same area. Instead of the preserved remnants of the actual animal's body, trace fossils offer us indirect proof of life in the past in the form of animal footprints, tracks, burrows, borings, and feces.

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Even though our planet has a lot of water, some areas don't experience rain much and they aren't close to large bodies of water.

So in those areas they don't get to drink much water, because there isn't much available.

We may have a unlimited supply of water, but in other countries they might not. Hot, humid area's that don't experience rain won't have any water to drink, so they go to extreme measures and drink from cactus, or eat cactus fruit.

Also, most of the water on earth isn't drinkable which can cause sickness.

All of them are very reactive.

As sunlight heats Venus' surface, the surface radiates infrared energy that is kept from escaping the planet by dense carbon dioxide atmosphere. This is called the greenhouse effect.

The High tempatures on Venus are caused by the Greenhouse effect

The volume of water measured using the graduated cylinder is not exactly identical identical to the volume calculated.

Calculated volume is theoretical value calculated from the density and mass of water.

But volume measured in cylinder can contain the personal error of individual.

Because in graduated cylinder volume is measured in a specific way that is:

Hey there!

A neutron is found in the nucleus of an atom. All neutrons have a neutral charge while protons have a positive charge, and electrons have a negative charge.

I hope this helps! Have a sparking day!

A neutron has no charge and is electrically neutral.

The neutron is an electrically neutral subatomic particle with no charge. It is neither positively charged nor negatively charged.

This makes it different from the proton, which carries a positive charge, and the electron, which carries a negative charge.

Neutrons are found in the nucleus of an atom along with protons.

Their mass is slightly greater than that of a proton.

For example, the neutron has a mass of 1.0087 atomic mass units (amu) while the proton has a mass of 1.0073 amu.

The seaweed would be the producer in this exact food web.

Since the seaweed is the main source of food in that food web, it supplies everything else in the food web by supplying the animal that eats it, which supplies the animal that eats that animal, and so on.

Confusing, right?

Have a great day :)

Answer: seaweed

Explanation:

it’s the only plant in this food web

Answer:- D.  [tex]Li_2CO_3(aq)+FeCl_2(aq)\rightarrow 2LiCl(aq)+FeCO_3(s)[/tex]

Explanations:- In chemical equations, (aq) stands for aqueous, (l) stands for liquid, (g) stands for gas and (s) stands for solid. In double replacement reactions, (aq) means soluble and (s) means insoluble that is precipitate.

Looking at all the equations, it is only the last equation that has a solid product and so this is the only precipitation reaction. A precipitate for Iron(II)carbonate is formed in it.

Answer:

The correct answer is

D.  Li2CO3(aq) + FeCl2(aq) → 2LiCl(aq) + FeCO3(s)

I believe an interaction between the biosphere and the atmosphere would be precipitation. Respiration is the process of breathing, and crystallization is the process of, well, crystallizing. :)

C. Sulfur

Is the answer.

your answer is sulfur because the atomic number is the same as protons!

plz mark as brainliest

Final answer:

Precision is the term that describes how closely a set of measurements are to each other, indicating the reproducibility of the measures under similar conditions. It differs from accuracy, which measures how close a measurement is to the true value. So the correct option is d.

Explanation:

The measure of how closely a set of measurements are to each other is best defined by the term precision. Precision refers to the reproducibility of measured values when repeated under similar conditions and indicates how close the measurements are to each other. It's important to note that precision is different from accuracy, which is a measure of how close a single measurement is to the correct or true value. Conversely, uncertainty is related to the potential variation in the measurements from the true value, providing an estimate of the range within which the true value lies.

Atoms of Cr in 0.86 mol of K2CrO4 = 0.86 × 6.02*10^23 = 5.177 * 10^23 atoms.

To find the number of atoms of chromium in 0.86 mol of potassium chromate, you multiply the moles by Avogadro's number, resulting in approximately 5.18 x 10²³ Cr atoms.

To calculate how many atoms of chromium are in 0.86 mol of potassium chromate (K₂CrO₄), we have to understand the composition of the compound potassium chromate. Potassium chromate consists of two potassium (K) ions, one chromium (Cr) atom, and four oxygen (O) atoms. Since there is one Cr atom in each formula unit of K₂CrO₄, the number of Cr atoms will be equal to the number of moles of K₂CrO₄ given.

To find the number of Cr atoms, we use Avogadro's number, which states there are approximately 6.022 x 10²³atoms in one mole of any substance. Therefore, we calculate the number of atoms of chromium by multiplying the number of moles of K₂CrO₄ by Avogadro's number:

Number of molecules = Number of moles × Avogadro’s number

Number of molecules = 0.86moles×(6.022 × 10²³ molecules/mol)

Number of molecules ≈ 5.18 × 10²³ molecules

Hey there!

The pH of a weak base (in this case, pyridine is a weak base) is calculated by using the weak base equation, and then solving it.

C5H5N; Kb= 1.7 x 10⁻⁹

pH = -log [H⁺]

we can also say that pH = 14 + log [OH⁻]

Plugging into the weak base equation, we know that Kb = [OH⁻][BH⁺] / [B]

This can be solved using an ice chart, which will then simplify to :

Kb = [x][x] / [0.50-x]

We can assume that x is very small in comparison to the 0.5 , so we consider it zero.

Then plug in and solve for x.  1.79 *10-9 = x² / 0.5

x = 2.992 * 10⁻⁵

ince X is equal to the [OH⁻] concentration, we can plug it into the second pH equation, and get the pH!

pH = 14+ log 2.99 * 10⁻⁵

pH = 9.48

Hope that helps!

The pH of a 0.65 M solution of pyridine (C₅H₅N) is 9.52.  

The equation for the protonation of the base pyridine is the following:

C₅H₅N + H₂O ⇄ C₅H₅NH⁺ + OH⁻   (1)

The constant of the above reaction is:

[tex] K_{b} = \frac{[C_{5}H_{5}NH^{+}][OH^{-}]}{[C_{5}H_{5}N]} = 1.7 \cdot 10^{-9} [/tex]    (2)

To calculate the pH of the solution we need to use the following equation:

[tex] pH + pOH = 14 [/tex]      

[tex] pH = 14 - pOH = 14 - (-log[OH^{-}]) = 14 + log[OH^{-}] [/tex]   (3)

So, we need to find the concentration of the OH⁻ ions. Since pyridine is a weak base, at the equilibrium we have (eq 1):

C₅H₅N  +  H₂O  ⇄  C₅H₅NH⁺  +  OH⁻

0.65 - x                          x              x

After entering the values of [C₅H₅N] = 0.65-x, [C₅H₅NH⁺] = x, and [OH⁻] = x, into equation (2) we can find the concentration of OH⁻:

[tex] 1.7 \cdot 10^{-9} = \frac{[C_{5}H_{5}NH^{+}][OH^{-}]}{[C_{5}H_{5}N]} = \frac{x*x}{0.65 - x} [/tex]  

[tex] 1.7 \cdot 10^{-9}(0.65 - x) - x^{2} = 0 [/tex]  

Solving the above quadratic equation for x, we have:

[tex] x_{1} = -3.32 \cdot 10^{-5} M [/tex]

[tex] x_{2} = 3.32 \cdot 10^{-5} M [/tex]        

We can calculate the pH, after taking the positive value, x₂, (concentrations cannot be negative) and entering into equation (3):

[tex] pH = 14 + log[OH^{-}] = 14 + log(3.32 \cdot 10^{-5}) = 9.52 [/tex]  

Therefore, the pH of the solution of pyridine is 9.52.

Find more about pH here:

I hope it helps you!    

Electron cloud model

Answer:

Electron cloud model

Explanation:

on edge

Ok. Sodium is used in the everyday things we eat or known as naCI. It is also used a reactor for nuclear things. It is also added to snow to de-ice the roads in winter.

In a covalent bond, two atoms are held together by the attraction between each atom and the shared electrons. the number of covalent bonds that an atom can form depends on the number of valence electrons in the atom.

hope dis helped u daddy

Answer: each atom and the shared electrons,

valence electrons

Explanation: A covalent compound is defined as the compound which is formed from the sharing of electrons between the element that are combining together.

These compounds are most likely to be formed when two non-metals combine together. For Examples: [tex]F_2[/tex]

Flourine is an element with tomic number 9 and has 7 valence electrons

[tex]F:9:1s^22s^22p^5[/tex]

Thus for formation of  a [tex]F_2[/tex] molecule, they share their valence electrons and attain stable configuration.

Answer:

Conceptual model - a diagram that shows the shape of the magnetic field around an object

Physical model - several balls and sticks glued together to represent a molecule

Virtual model - a computer program that shows all possible planetary orbits

Mathematical model - an equation that shows how an object’s acceleration relates to its mass

Explanation:

happy to help :^)

The correct pairings of conceptual models with their corresponding examples:

A physical model is a copy or imitation of something that helps us see and understand its features, how it behaves, or its design. Physical models are objects that you can touch and are in three dimensions. They can be similar to a smaller version of a building or simple objects like balls and sticks that represent molecules.

A virtual or computer-made picture  of something that you can use to study and interact with. Virtual models are frequently used in simulations and computer programs to imitate real-life events or situations. An example is a computer program that displays how planets move in their paths around the sun.

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A longer lifespan typically implies a higher chance of producing offspring because it provides a larger timeframe for successful reproduction. Organisms with extended lifespans have more opportunities to reproduce and can therefore often result in a larger overall number of offspring.

In the context of biological evolution, a longer life span generally signifies a higher chance of producing offspring. This is primarily because an organism with a longer life span has a longer period of reproductive viability, i.e., the timespan within which it can reproduce successfully. This increased amount of time for possible reproduction results in more opportunities to produce offspring, thus potentially leading to a larger overall number of offspring throughout the organism's lifetime.

Furthermore, this concept of a longer life span equating to more offspring is often seen in organisms such as turtles and many species of trees. These organisms live for many decades, or even centuries, and during this extended lifespan, they continue to reproduce, which increases their chances of having more offspring compared to organisms with shorter life spans.

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Answer: 197 grams

Explanation:

According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.

To calculate the moles, we use the equation:

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar Mass}}=[/tex]

Given mass = 405 g

Molar mass = 78.07 g/mol

[tex]\text{Number of moles}=\frac{405g}{78.07g/mol}=5.19moles[/tex]

1 mole of [tex]CaF_2[/tex] contains = 2 moles of fluorine

5.19  mole of [tex]CaF_2[/tex] contains = [tex]\frac{2}{1}\times 5.19=10.38moles[/tex] of fluorine

Mass of flourine =[tex]moles\times molar mass=10.38\times 19=197g[/tex]

Thus 197 grams of F are in 405 grams of [tex]CaF_2[/tex] .

The number  of hydrogen atoms that are in 7.80 moles of ammonium sulfide are  3.756 x 10^25  atoms

calculation

Step  1:  calculate  the  moles of H  in  (NH4)2S

 since there are 8 atoms of  H in (NH4)2S  the moles of

   H =  8 x7.80 =  62.4  mole

 Step  2: use of Avogadro's law  constant  to  determine the number  of  H atom

          that is 1 mole = 6.02 x10^23 atoms

                     62.4 moles=?  atoms

= [ 62.4  x 6.02 x10^23]/  1 mole= 3.756  x10^25    atoms

Answer: There are [tex]3.75 \times 10^{25}[/tex] number of H atoms in 7.80 mol of ammonium sulfide.

Explanation:

The formula of ammonium sulfide is [tex](NH_{4})_{2}S[/tex].

There are 2 nitrogen atoms, 8 hydrogen atoms and 1 sulfur atom in one molecule of ammonium sulfide.

Calculate moles of hydrogen atoms as follows.

              [tex]8 \times 7.80[/tex] = 62.4

According to Avogadro's number 1 mole contains [tex]6.022 \times 10^{23} atoms[/tex]

Therefore, calculate number of H atoms as follows.

               [tex]62.4 \times 6.022 \times 10^{23}[/tex]

             = [tex]375.77 \times 10^{23}[/tex]

             = [tex]3.75 \times 10^{25}[/tex]

Thus, there are [tex]3.75 \times 10^{25}[/tex] number of H atoms in 7.80 mol of ammonium sulfide.

When describing the velocity of an object, you must specify the both the speed and the direction.

That’s because velocity is a vector: it has both magnitude (speed) and direction.

If you say that a object is travelling southwest at 70 km/s, you are giving its velocity.

If you say that it is travelling at 70 km/s, you are giving its speed.

Final answer:

To describe the velocity of an object, you must specify the magnitude of speed and its direction, reflecting that velocity is a vector quantity unlike speed, which is scalar.

Explanation:

To describe the velocity of an object, one must specify two key things: (1) the magnitude of the speed, which is a scalar quantity representing how fast the object is moving, and (2) the direction of travel, which informs us of the orientation of the object's motion in space. For example, an object moving at 20 meters per second towards the north has a velocity that can be expressed as '20 m/s north'. This descriptive pairing of speed and direction is what differentiates velocity from speed, making velocity a vector quantity.

When illustrating velocity, a vector representation is often used, which is not always to scale but indicates direction and relative magnitude. For instance, in the case of the two airplanes with different speeds and directions discussed in the question, their velocities can be represented by arrows with lengths proportional to their speeds and pointing in the respective directions of travel - northeast and southwest.

Answer:

c fluorine

Explanation:

1) Balanced chemical reaction:

2HClO₄(aq) + K₂CO₃(aq) → K₂CO₃(aq) + CO₂(g) + H₂O(l).

2) Balanced chemical reaction:

HC₂H₃O₂(aq) + LiHSO₃(aq) → LiC₂H₃O₂(aq) (aq) + SO₂(g) + H₂O(l).

3) Balanced chemical reaction:

(NH₄)₂SO₄(aq) + Ca(OH)₂(aq) → CaSO₄(s) + 2NH₃(g) + 2H₂O(l).

CaSO₄ (calcium sulfate) is insoluble in water.

1) Aqueous perchloric acid reacts with aqueous potassium carbonate to form aqueous potassium perchlorate, carbon dioxide gas and water.

2HClO₄(aq) + K₂CO₃(aq) → 2KClO₄(aq) + CO₂(g) + H₂O(l).

2) Aqueous acetic acid reacts with aqueous lithium bisulfite to form aqueous lithium acetate, sulfur dioxide gas and water.

HC₂H₃O₂(aq) + LiHSO₃(aq) → LiC₂H₃O₂(aq) + SO₂(g) + H₂O(l).

3) Aqueous ammonium sulfate reacts with aqueous calcium hydroxide to form a white precipitate of calcium sulfate, ammonia gas and water.

(NH₄)₂SO₄(aq) + Ca(OH)₂(aq) → CaSO₄(s) + 2NH₃(g) + 2H₂O(l).

Is Does not have a Coefficient so it would be No

i will say ar that all i got

NOBLE GAS IS THE ANSWER

Answer:

has 17 electrons

Explanation:

Chlorine is a halogen that belongs to the 17th group on the periodic table. Chlorine has an atomic number of 17. The atomic number of elements is used in placing and locating elements on the periodic table. In fact, the periodic arrangements of elements is as a result of their atomic numbers.

The atomic number is the number of protons in an atom. This number is the same as the number of electrons in a neutral atom that has not gained or lost any electron.

It is correct to say chlorine has 17 electrons and they occupy 3 electronic shells.

Answer:

Has 17 electrons.

Explanation:

I got this right on a test.

Page 1  

1: The grass

2: The grasshopper

3: The frog

4: The snake

5: The eagle

Page: 2

The answer is the 2nd one

Page: 3

The owl would because its at the end it would have almost no more sun energy left in whatever it eats.

Hope This Helps :)

Grass, Grass Hopper, Frog, Snake, then Hawk.

For the food web question, it would be the third option because most organisms eat more than one thing.

The original source of energy in most ecosystems is the sun.

The owl would receive the least amount of energy because each level of the food chain only gains 10% of the organisms energy.