In order for a chemical reaction to take place, a certain amount of _____ must be present.

Answer: The answer is D, uneven heating of the Earth by the Sun.

Answer:

I think its b part or none of above

Answer:

a because the others whould cause earthquakes

Explanation:

Answer:

A

Explanation:

because i think is A (if is not im sorry )

Answer:

It will take 22920 years to decay 112.5 g of 120 grams.

Explanation:

Answer:

The answer is C.  Because particles can never stop moving

Explanation:

"All matter has thermal energy, even matter that feels cold. That's because the particles of all matter are in constant motion and have kinetic energy."

Answer is C

A synthesis reaction looks like this:

A+ B → AB

Answer:

Because the exact position of the electron is not known,it must be assumed that the electron takes up the entire space in an orbital.

Explanation:

Answer:  the answer is C. The warmer object's particles speed up

the cooler object's particles.

Explanation:    Conduction occurs when a substance is heated, particles will gain more energy, and vibrate more. These molecules then bump into nearby particles and transfer some of their energy to them. This then continues and passes the energy from the hot end down to the colder end of the substance.

Answer:

morlecular element is oxygen

Answer:

Our process would be just turning the molecules of sucrose to the moles by dividing using Avogadro's number (6.02 x 10^23), which will give us the moles we need. In order to find the mass of the sucrose, you have to multiply the moles by the molar mass of sucrose in order to find the mass, and then multiply by it 1000 to change it to mg.

Here are the formulas:

Number of moles = Number of molecules / Avogadro's number

Mass = Moles x Molar mass

Number of moles = (1.4 x 10^17) / (6.02 x 10^23) = 2.3255814 x 10^-7 moles

Now that we have the moles, we can multiply them by Sucrose's molar mass, which can be calculated by using the masses listed in the periodic table.

Carbon's Molar Mass = 12g/mol (There are 12 atoms of Carbon in sucrose)

Hydrogen's Molar mass = 1.01g/mol (22 atoms of Hydrogen in sucrose)

Oxygen's Molar mass = 16g/mol (11 atoms of oxygen in sucrose)

Now we just add them together:

((12)x(12)) + ((1.01)x(22)) + ((16)x(11)) = 342.22g/mol is the molar mass of Sucrose

Now back to the question, you multiply the moles of sucrose by its molar mass to get the mass in grams

(2.3255814 x 10^-7) x (342.22) = 0.0000796 grams

Now to get it in milligrams, you multiply the answer above by 1000

0.0000796 x 1000 = 0.079 mg (already in 2 sig figs)

Therefore there are 0.079 milligrams of sucrose in the sugar crystal.

The mass of sucrose molecules is  0.079 milligrams .

To calculate mass of a substance wherein number of molecules is given, initially number of moles is obtained.

number of moles= number of molecules/Avogadro's number

=1.4×10¹⁷/6.022×10²³

=2.234×10[tex]^-7[/tex]

Now the mass is calculated  by multiplying number of moles into molar mass of sucrose

=2.234×10[tex]^-7[/tex]×342.22

=795.31 ×10[tex]^-7[/tex] g

=0.079 mg.

The mole concept is a convenient method for expression of amount of substance in chemical applications.It is mainly focused on the quantity  of mole which is a count of large number of particles.One mole of  any substance is equal to the Avogadro's number .

It is useful for measuring products of chemical reaction. It is the basis of stoichiometry and expresses amount of reactants and products  which are formed and consumed during the course of chemical reaction.

Learn more about mole concept ,here:

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Answer:

RBCs are disc-shaped with a flatter, concave center. This biconcave shape allows the cells to flow smoothly through the narrowest blood vessels. ... Many RBCs are wider than capillaries, but their shape provides the needed flexibility to squeeze through

Answer: It is conserved.

Explanation: When the box is pushed across the floor, then floor and box becomes warm which resembles the condition of conservation of energy.

The given problem can be resolved by the concept of energy conservation. The statement of energy conservation says that, "Energy is neither be created nor be destroyed, but it is converted from one form to another.

In the given problem, the person pushes the box across the floor, such that the mechanical energy from the moving arms of person is transferred to the box, and the box and floor becomes warm.

During this process, the energy from the person moving arm is transferred to the box in the form of kinetic energy. And thus kinetic energy is then being transferred to thermal energy or heat energy, due to which the box and floor becomes warm.

Thus, we can conclude that the given case reflects the process of transformation of energy from one state to another, which highlights that during the process, energy is conserved.

Answer:16g

Explanation:A solution's percent concentration by mass,

% w/w

, basically tells you what mass of solute you get per

100 g

of solution.

Answer: All options (I, II, III, IV, V)

Explanation: The answer is all options because they never reach equilibrium or intersect at a region as the both decrease at the same rate.

Answer: Picture shows the correct one

Explanation:

Considering the reaction stoichiometry, 0.00495 grams of water is produced when  2.75×10⁻⁴ moles of NaOH reacts completely.

Sodium hydroxide (NaOH) and hydrochloric acid (HCl) react to form sodium chloride (NaCl) and water. So, the balanced reaction is:

NaOH + HCl → NaCl + H₂O

By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:

In the periodic table, you can find the molar mass of the elements, also called atomic mass or atomic weight. So, to calculate the molar mass of a compound, you must add the molar mass of the elements of the compound multiplied by the times they appear in the compound.

So, in the case of water:

H₂O= 2× 1 g/mole + 16 g/mole

H₂O= 18 g/mole

Then, if by stoichiometry of the reaction 1 mole of water is produced, the mass of water produced is calculated as:

mass H₂O= 1 mole× 18 g/mole

mass H₂O= 18 g

Then you can apply the following rule of three: if by stoichiometry 1 moles of NaOH produce 18 grams of H₂O, 2.75×10⁻⁴ moles of NaOH will produce how much mass of H₂O?

[tex]mass of H_{2} O=\frac{2.75x10^{-4} moles of NaOHx18 grams of H_{2} O}{1 mole of NaOH}[/tex]

mass of H₂O= 0.00495 grams

In summary, 0.00495 grams of water is produced when  2.75×10⁻⁴ moles of NaOH reacts completely.

Learn more about stoichiometry:

Answer:

3 elements are present in thr compound

Answer:

metallic bond, force that holds atoms together in a metallic substance. The atoms that the electrons leave behind become positive ions, and the interaction between such ions and valence electrons gives rise to the cohesive or binding force that holds the metallic crystal together.

Explanation:

Answer:

about 4 or 4.8

Explanation:

Answer:

Color change, formation of bubbles, and temperature change

Answer:

droplets of sulfuric acid

Explanation:

The types of mixtures are homogeneous and heterogeneous, you can identify these based on their features.

A mixture occurs when two or more materials are mixed or combined. For example, if you combine two or more liquids. Moreover, this can lead to two types of mixtures:

Each of these has defined features that affect the characteristics and properties of a mixture:

Homogenous mixtures:

Heterogeneous mixture:

Note: This question is incomplete because of this, I answered based on general knowledge.

Learn more about mixtures in: https://brainly.com/question/24898889

Answer:

uranium

Explanation:

The heaviest naturally stable element is uranium, but over the years physicists have used accelerators to synthesize larger, heavier elements. In 2006, physicists in the United States and Russia created element 118.

Answer:

Uranium

Explanation:

Naturally its uranium, however scientists are artificially making bigger ones (which aren't on the periodic table).

Hope this helps!

Answer:

compounds

Explanation:

Answer:

I cant do it for you but to help you I can tell you this The charged particles can move only when there is a complete conducting pathway (called a 'circuit' or 'loop') from one terminal of the battery to the other.

Explanation:

A spectrum is a  pattern is unique to a substance and can be used identify it.

According to Max Plank, energy occurs in packets called quanta. Hence, energy is not continuous but takes on discrete values which are integer multiples of a fundamental amount.

Again, when a substance is given light energy, a characteristic fingerprint is obtained. This pattern is unique to the substance that has it. These characteristics “fingerprints” are called spectrums.

Learn more: https://brainly.com/question/6284546

Answer:

7.8286e+23

Explanation:

Use Avogadro's number

Answer:

a) Fe

b) Fe

c) Fe

Explanation:

When using their stoichiometric ratios, in all of the the iron will run out before the oxygen, making the iron the limiting reactant.

Answer:renewable resources

Explanation:

Answer= C) CN contains a covalent bond.