a chemist has a block of iron metal (density is 7.87 g/ml). the block weighs 1.90 g. what is the volume of the iron block in ml?

Answer: Be, Ca, Ra

Explanation:

Elements are distributed in groups and periods in a periodic table.

Elements that belong to same groups will show similar chemical properties because they have same number of valence electrons.

Berrylium (Be) , Calcium (Ca) and radon (Rn) are elements which  belong to Group 2. They have 4, 20 and 88 electrons respectively and contain 2 valence electrons each and thus can lose two electrons to complete their octet. Thus they will show similar chemical properties.

The chemical reactivity of elements is governed by the valence electrons present in the element.

Answer:Accounting for the sizes of protons, neutrons, and electrons, most of the volume of an atom—greater than 99 percent—is, in fact, empty space. ... The electrons that surround all atoms are negatively charged and cause atoms to repel one another, preventing atoms from occupying the same space.

Explanation: hope this helped

Answer:

thermal conductivity: the rate at which heat is transferred by conduction through a unit cross-section area of a material, when a temperature gradient exits perpendicular to the area

electrical conductivity: the measure of the amount of electrical current a material can carry or it's ability to carry a current

solubility: the ability to be dissolved, especially in water

magnetism: a physical phenomenon produced by the motion of electric charge, resulting in attractive and repulsive forces between objects

melting point: the temperature at which a given solid will melt.

boiling point: the temperature at which a liquid boils and turns to vapor

Explanation:

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The value of 'a' is 7.9

Chemical equations - chemical equations are symbolic depictions of chemical reactions where the reactants and products are stated in terms of their respective chemical formulae.

Balancing of chemical equation is necessary because the law of conservation of mass states that during a chemical reaction, matter cannot be generated or destroyed. This is only conceivable if the total number of atoms on the reactants' and products' sides is identical. A chemical reaction should therefore always be in balance.

According to the given equation-

2a = 135 - 15a

2a + 15a = 135

17 a = 135

a = 135/ 17

a = 7.9

You can solve it by simply transferring the variables on one side and the constants on the other side. When you transfer -15 a on the left side it becomes =15a. now, 2a + 15 a is 17 a.

For taking out the value of 'a' simply divide 135 by 17.

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Answer: exothermic reaction

The monster is releasing heat energy to the environment surrounding it. The term "exo" means "outside".

In contrast, an endothermic reaction is one where energy is absorbed from the environment to cool down the surrounding air.

Answer: Oxygen - 18 atom contains 8 protons.

Explanation:

The number of protons is the same as the atomic number. In isotopes, only the neutrons vary, but the protons always remain the same.

Answer:

heterogenous mixture i believe.

Explanation:

Explanation:

is b or c but i think asnwer is b

The correct statement is " Models are used to explain how something works."

To introduce specific content, models might be employed. A model can help students learn crucial words and create a setting in which they can investigate pertinent processes.

Models can be used to improve explanations, promote discussion, make predictions, present graphical images of abstract concepts, and generate mental models in research.

Therefore, Models are used to explain how something works .

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Answer:

B) It is bent because there are four bonded pairs around carbon.

Explanation:

Since carbon forms a single bond with all four chlorides (four domains), the shape and geometry will both be tetrahedral. There are no lone pairs of electrons that cause the shape to appear bent.

Its tetrahedral because there are four bonded pairs around carbon. This explains the VSEPR geometry of a carbon tetrachloride molecule. Therefore, the correct option is option B.

The acronym VSEPR (pronounced "vesper") is frequently used to refer to the model known as Valence Shell Electron Pair Repulsion Model. The model essentially predicts the shape of molecules. In particular, organic compounds and polyatomic ions' bonding & molecular geometry are examined by VSEPR models. Almost all compounds with a central atom which is not a metal can benefit from it.

Due to their two-dimensionality, Lewis structures can only reveal the quantity and kind of atom-atom bonds. The 3-D shapes of ions and molecules are predicted by the VSEPR model, but it is unable to offer any exact details on the bond length and the bond itself. Its tetrahedral because there are four bonded pairs around carbon. This explains the VSEPR geometry of a carbon tetrachloride molecule.

Therefore, the correct option is option B.

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The mole fraction of 195 g AlCl3 in 240 mL of water is 0.099.

Mole fraction is the ratio of the number of moles of a particular component to the total number of moles in the mixture. To determine the mole fraction of AlCl3, the mass of AlCl3 will be converted to moles and the number of moles of water must be determined. Since the amount of water used is expressed in volume, we will be using the density of water to determine the mass of water for a given volume.

Solving for the moles of AlCl3:

moles AlCl3 = mass AlCl3 / molar mass of AlCl3

moles AlCl3 = 195 g / 133.33 g/mol

moles AlCl3 = 1.4625 mol

Solving for moles of water:

A commonly used density of water is 1 g/mL.

240 mL of water * (1 g/mL) = 240 g of water

moles water = mass water / molar mass water

moles water = 240 g / 18.02 g/mol

moles water = 13.32 mol of water

Mole fraction = mol AlCl3 / ( mol AlCl3 + mol water)

Mole fraction = 1.4625 / {1.4625 +13.32)

Mole fraction of AlCl3 is 0.099

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Answer:

electron, proton, nucleus, atom, molecule teacher

Answer:

There is no chemical symbol for paper since it is not an element but rather a mixture of several different compounds. Mixtures in two or more phases are heterogeneous mixtures.

Explanation:

Answer:

You can make Cake CAke Cake Cake and other stuff too Ig

Explanation:

Answer:

D

Explanation:

Answer:

C - Up and Down in a Circle

Explanation:

Waves are actually energy passing through the water, causing it to move in a circular motion. When a wave encounters a surface object, the object appears to lurch forward and upward with the wave, but then falls down and back in an orbital rotation as the wave continues by, ending up in the same position as before the wave came by.

Answer:

organic compounds are classified based on functoin group

Explanation:

functional group is part of molecule or compound that determine the properties of that molecule or compound.

In chemistry, organic compounds are substances that have a covalently linked carbon atom. These compounds are classified based on the functional group and structures.

Organic compounds are said to be the compounds that have the presence of the carbon atom/s linked to the other atoms including nitrogen, oxygen, and hydrogen through a covalent bond.

The organic compounds are classified based on their structures and functional groups attached to their side chains. The functional groups include alkynes, alkenes, alcohols, carbonyl, nitriles, amines, etc.

The compounds can also be categorized based on the open or closed chain structures that can be homocyclic or heterocyclic. Further, the compounds can be aromatic or alicyclic.

Therefore, organic compounds are classified based on their functional groups and structures.

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Answer:

Well, it depends on where they are orbiting! Planets that orbit closer to the Sun than Earth have shorter years than Earth. Planets that orbit farther from the Sun than Earth have longer years than Earth.

Answer:

covalent bond

Explanation:

hope this helps :D

Answer:

99.3%

Explanation:

The percent by mass of the solute can be expressed as:

And for this problem:

So to calculate the percent by mass first we need to calculate the mass of water, to do so we use its density (1 g/L):

Density water = mass water / volume

Now we have all the data required to calculate the % mass:

Answer: 14.3

Explanation:

Answer:

I know the answer, but it is hard to explain

Explanation:

yIt easy u but the single letter in the outside boxes. Then u but the one in the middle box. But the BB in one corner. then but bb on the opposite corner. Then but Bb on the other box.

Answer:

father.....Bb

mother.....bb

offspring, 50%Bb brown eyes ,50%bb blue eyes

Answer:

Nuclear fission

Explanation:

Even though the equation is not too clear, however, we can see that the uranium nucleus was bombarded with a particle leading to its disintegration to yield other nuclides.

A nuclear fission reaction is one in which a heavier nuclide is bombarded with a particle (usually a neutron) leading to the disintegration of that nuclide into other nuclides with the release of tremendous energy. More neutrons are released in the process to continue the reaction. Hence, it is a chain reaction.

We will need to know Avogadro's number and the molar mass of sucrose for this problem to do dimensional analysis.

250g × [tex]\frac{1 mol}{342.297g}[/tex] × [tex]\frac{6.022 * 10^{23} molecules}{1 mol}[/tex] = 4.398 molecules

There are 4.398 sucrose molecules in 250 grams of sucrose.

Answer:

Explanation:

Alge. Waste and dead things

what is wrong with you how cant you do this I'm not being mean I'm just asking dont answer if you dont want to its ur life

fluorine, F2, chlorine, Cl2, bromine, Br2, or iodine, I2

Answer:

.

Explanation:

Answer:

1) In fusion reactions, two light atomic nuclei fuse together to form a heavier nucleus. In doing so, they release a comparatively large amount of energy that arises from the binding energy, creating an increase in temperature of the reactants.

2) iron-56

3) When a large, fissile atomic nucleus such as uranium-235 or plutonium-239 absorbs a neutron, it may undergo nuclear fission.  However, one neutron does collide with an atom of uranium-235, which then splits and releases two neutrons and more binding energy.

4) Iron cannot release energy by fusion because it requires a larger input of energy than it releases.  This energy blows the outer layers of the star off into space in a giant explosion called a supernova (plural: supernovae.)

have you tried   G o o g l e

Scientists discover that rocks farther away from the mid-ocean ridge were older than those near it by C. determining the age of rock samples obtained by drilling on the seafloor.

According to the scientists, it was noted that new oceanic crusts were formed at the mid-ocean ridges. When it cools down, then the magnetic field during its formation is recorded.

The magnetic stripes become older when they move away from the mid-ocean ridge. The geologic dating technique was used in the seafloor rocks. It was found that the youngest rocks were at the mid-ocean ridges while the rocks get older due to their distance from the ridge crest.

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Answer:D-when explaining and documenting their work

Explanation:I took the k-12 test and got it right!:) Hope this helps!!!!

Scientists can engage in various activities in various sequences. It can be best explained by documenting and explaining their work. Thus, option D is correct.

The scientific method has been a series of events that uses observed phenomena to conduct research by testing the hypothesis that raises the question. It conducts the experiment and reaches the results to conclude the findings.

In various scientific sequences, scientists can be engaged at a time similar to explaining and documenting the work involves representation of the proper rationale and its deep and thorough explanation so to justify the hypothesis and its accountability.

Therefore, option D. the explanation and documentation are the various activities involved in different sequences.

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