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Answer: chemical element

Explanation: A chemical element is a substance that contains only one type of atom, which is the smallest particle of an element.

Answer:

The ice cubes gain energy

Explanation:

The ice cubes are gaining energy from the water's carbon dioxide, or H2O. They then melt because they cannot hold that energy.

Answer:

True

Explanation:

Hydrogen is one of the most abundant elements in the universe so yes

Answer:

true

Explanation:

Hydrogen is an chemical element

Answer:

1

Explanation:

single displacement replaces one element with another and it's product is a pure element.

Answer:

A diamond contains 5.0 x 10 21 atoms of carbon.

Answer:

Generate concept.

Explanation:

The process of designing includes many processes out of which the process of developing the idea for a new product is called Generate concept.

Product idea( concept) generation is a act that begins with a list of criteria set by the client regarding his necessities and preferences. Based on the criteria, concept generation aims to pinpoint a range of potential ideas and solutions that addresses those needs.

Answer: The freezing point depression is [tex]1.86^0C[/tex]

Explanation:

Depression in freezing point is given by:

[tex]\Delta T_f=K_f\times m[/tex]

[tex]\Delta T_f[/tex] = Depression in freezing point

[tex]K_f[/tex] = freezing point constant = [tex]1.86^0C/m[/tex]

m= molality = [tex]\frac{\text {moles of solute}}{\text {mass of solvent in kg}}=\frac{2mol}{2kg}=1m[/tex]

[tex]\Delta T_f=1.86mol/kg^0C\times 1m[/tex]  

[tex]\Delta T_f=1.86^0C[/tex]  

Thus freezing point depression is [tex]1.86^0C[/tex]

Answer:

false

Explanation:

Answer:

bang on a drum

Explanation:

Answer:

Bang on drum

Explanation:

Its right.

Answer:

scavenger or consumer

Explanation:

they collect and gather fruits, and different wild life

Answer:

La energía necesaria para calentar el bloque de aluminio es 54927 J.

Explanation:

Se denomina calorimetría a la medición y el cálculo de las cantidades de calor que intercambia un cuerpo o un sistema.

De esta manera, entre el calor y la temperatura existe una relación de proporcionalidad directa (Dos magnitudes son directamente proporcionales cuando existe una constante de manera que cuando una de las magnitudes aumenta, la otra también; y lo mismo ocurre cuando alguna de las dos disminuye.). La constante de proporcionalidad depende de la sustancia que constituye el cuerpo como de su masa, y resulta el producto del calor específico por la masa del cuerpo. Entonces, la ecuación que permite calcular intercambios de calor es:

Q=c*m*ΔT

Donde Q es el calor intercambiado por un cuerpo de masa m, constituido por una sustancia de calor específico c y donde ΔT es la variación de temperatura.

En este caso:

Reemplazando:

Q= 0.9 [tex]\frac{J}{g*C}[/tex]*850 g* 71.8  C

y resolviendo se obtiene:

Q= 54927 J

La energía necesaria para calentar el bloque de aluminio es 54927 J.

Answer:

For 1, your answer is b. absorbs, endothermic. For 2, your answer is a. a solution becomes more dilute.

Explanation:

I took the test.

Answer:

DNA

Explanation:

Genetic material DNA is passed from cell to cell.

DNA is Deoxyribonucleic acid. It is a polymer composed of two polynucleotide chains. These chains coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of all known organisms and many viruses. It keeps on transferring from generation to generation. Two types of Nucleic acids are DNA and ribonucleic acid.

In DNA, 4 bases are present that are Adenine, Guanine, Cytosine and Thymine. Whereas Thymine is replaced by Uracil in case of RNA.

These bases are connected by hydrogen bonds with each other.

The configuration of the DNA molecule is highly stable, allowing it to act as a template for the replication of new DNA molecules, as well as for the production (transcription) of the related RNA (ribonucleic acid) molecule.

Therefore, Genetic material DNA is passed from cell to cell.

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Answer:

diple doble

Explanation:

Answer:

The correct answer is -

1. D. mold

2. A. Cast

3. F. trace fossil

4. C. original material fossils

5. B. fossil record.

Explanation:

Mold is the impression of an organism in a rock that occurs due to the complete dissolving of the organism and only an impression left in sedimentary rocks.

The cast is a fossil copy of an organism in a rock that takes place when water-containing minerals fill the molds and creates a three-dimension copy of the fossil.

Trace fossils are the fossils that are preserved in such a manner that records of biological activity stored only instead of remains of plants or animals.

Storing originals animals or parts of the remaining such as tissue of an organism in natural form is known as original-material fossils.

Fossil records are the fossils ever found or discovered on the earth.

Answer:

The answer is 0.01790670606142. We assume you are converting between moles Iron and gram.

Explanation:

The mass of 0.083 moles of iron to the nearest tenth is 0.4635135 grams.

Mass is defined as the amount of substance contained in a particle or object as a dimensionless quantity. An object's mass is the entire amount of matter it contains. A scalar quantity, it. By using beam balance, it is measured. The object's mass is constant everywhere it is. The inertia of an object allows us to calculate its mass.

One carbon-12 atom weighs exactly 12 atomic mass units, which equals its atomic mass. One mole of carbon-12 atoms weighs exactly 12 grams; this is known as the molecular mass of carbon-12.

Molar mass of iron is 55.847 moles

Molar mass = mass/mole

Mass = molar mass x mole

Mass = 55.845 x 0.083

Mass = 0.4635135 grams.

Thus, the mass of 0.083 moles of iron to the nearest tenth is 0.4635135 grams.

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Answer:

C. He feels excited and happy

Explanation:

Answer:

191.11 grams of oxygen gas should be produced.

Explanation:

The balanced reaction is:

2 Al₂O₃ → 4 Al + 3 O₂

By stoichiometry of the reaction (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:

Being the molar mass of each compound:

By reaction stoichiometry, the following mass quantities of each compound participate in the reaction:

Then you can apply the following rule of three: if by stoichiometry 108 grams of aluminum are produced along with 96 grams of oxygen, 215 grams of aluminum are produced along with how much mass of oxygen?

[tex]mass of oxygen=\frac{215 grams of aluminum*96 grams of oxygen}{108grams of aluminum}[/tex]

mass of oxygen= 191.11 grams

191.11 grams of oxygen gas should be produced.

Answer:

La constante de equilibrio Ka del ácido láctico es 1.38x10⁻⁴.

Explanation:

El ácido láctico es un ácido débil cuya reacción de disociación es la siguiente:

CH₃CHOHCOOH + H₂O ⇄ CH₃CHOHCOO⁻ + H₃O⁺   (1)

0.025M - x                                        x                     x                    

La constante de acidez del ácido es:        

[tex] Ka = \frac{[CH_{3}CHOHCOOH^{-}][H_{3}O^{+}]}{[CH_{3}CHOHCOOH]} [/tex]

Sabemos que la concentración del ácido inicial es:

[CH₃CHOHCOOH] = 0.025 M    

Y que a partir del pH podemos hallar [H₃O⁺]:

[tex] pH = -log[H_{3}O^{+}] [/tex]

[tex] [H_{3}O^{+}] = 10^{-pH} = 10^{-2.75} = 1.78 \cdo 10^{-3} M [/tex]

Debido a que el ácido se disocia en agua para producir los iones CH₃CHOHCOO⁻ y H₃O⁺ de igual manera (según la reacción (1)), tenemos:

[CH₃CHOHCOO⁻] = [H₃O⁺] = 1.78x10⁻³ M

Y por esa misma disociación, la concentración del ácido en el equilibrio es:

[tex] [CH_{3}CHOHCOOH^{-}] = 0.025 M - 1.78 \cdo 10^{-3} M = 0.023 M [/tex]

Entonces, la constante de equilibrio Ka del ácido láctico es:

[tex] Ka = \frac{[CH_{3}CHOHCOOH^{-}][H_{3}O^{+}]}{[CH_{3}CHOHCOOH]} = \frac{(1.78 \cdo 10^{-3})^{2}}{0.023} = 1.38 \cdot 10^{-4} [/tex]          

Espero que te sea de utilidad!  

Answer:

The sun would appear to move more slowly across Mercury's sky.

Explanation:

This is because, the time it takes to do one spin or revolution on Mercury is 176 days (which is its period), whereas, the time it takes to do one spin or revolution on the Earth is 1 day.

Since the angular speed ω = 2π/T where T = period

So on  Mercury, T' = 176days = 176 days × 24 hr/day × 60 min/hr × 60 s/min = ‭15,206,400‬ s

So, ω' = 2π/T'

= 2π/15,206,400‬ s

= 4.132 × 10⁻⁷ rad/s

So on  Earth, T" = 1 day = 1 day × 24 hr/day × 60 min/hr × 60 s/min = ‭‭86,400‬ s

So, ω" = 2π/T"

= 2π/86,400‬ s

= 7.272 × 10⁻⁵ rad/s

Since ω' = 4.132 × 10⁻⁷ rad/s << ω" = 7.272 × 10⁻⁵ rad/s, the sun would appear to move more slowly across Mercury's sky.

Answer:

Potassium Sulfide

Explanation:

K is more reactive than Fe which means K displaces Fe from the equation

Explanation:

Hi,

I don't think it can affect humans because humans and birds don't get into contact with each other. An insect and a human do, therefore a human could be affected, but a bird doesnt.

I hope this helps :)

Answer:

The following is a rather lengthy discussion on chemical stoichiometry, but it will lead you through the mole concept and its application to chemical reaction stoichiometry. The problems are different than the one posted, but if you can follow this, then you can work your problem of interest.

Explanation:

Stoichiometry is very easy to master if you understand the ‘mole concept’ and how it is used to define and describe chemical process mathematically. A ‘mole’ – in chemistry – is the mass of substance containing one Avogadro’s Number of particles. That is, N₀ = 6.023 x 10²³ particles / mole. When working with chemical reactions and equations data should be first converted to moles using the following conversions.  

1 mole = 1 formula weight = 6.023 x 10²³ particles = 22.4 liters at STP(0⁰, 1atm).

In this problem you are given the equation 2Na + 2H₂O => 2NaOH + H₂. ‘Reading the equation’ there are 2 moles of Na, 2 moles of water, 2 moles of NaOH and 1 mole of H₂. In another example 3H₂ + N₂ => 2NH₃ there are 3 moles of H₂, 1 mole of N₂ and 2 moles of NH₃. The mole values can be multiples or fractions but if one mole value increases all the remaining mole values increase or decrease proportionally. For example:

Using the equation 2Na + 2H₂O => 2NaOH + H₂, one could multiply the equation by 2 giving 4Na + 4H₂O => 4NaOH + 2H₂. The equation shows balance but is not in standard form. If one multiplies the equation by ½ gives Na + H₂ => NaOH + ½H₂. Again, the equation shows balance but is not in standard form.

Standard form of equation also implies the equation conditions are at 0⁰C & 1atm pressure and 1 mole of any gas phase substance occupies 22.4 Liters volume. Such is the significance of converting given data to moles as all other substance mass (in moles) are proportional.  

1st problem, 1.76 x 10²⁴ formula units of Na will react with water (usually read as an excess) to produce (?) grams of H₂.

1st write the equation followed by listing the givens below the respective formulas… That is…

                         Na                      +            H₂O       =>    NaOH    +    H₂,

Given:      1.76 x 10²⁴ atoms                excess             ---------          ? grams

               = 1.76 x 10²⁴atoms/6.023 x 10²³atoms/mole

               = 2.922moles                                        produces  =>    2.922moles H₂ (b/c coefficients of Na & H₂ are same)

                                                      Convert moles to grams =>    2.922moles H₂  x  2.000 grams H₂/mole H₂

                                                                                                              = 5.8443 grams H₂

2nd problem, 3.5 moles Na will react with H₂O (in excess) to produce (?) moles of NaOH.

Again, write equation and assign values to each formula unit in the equation.

                         Na                      +            H₂O        =>           NaOH    +    H₂,

Given:            3.5moles                       excess                      ? grams       ----

Since coefficients of balanced std equation are equal …

                      3.5 moles Na                          produces =>     3.5 moles NaOH

                                             Convert moles to grams =>     3.5 moles NaOH x 40 g Na/mole Na

                                                                                                  = 140 grams NaOH

3rd problem, 2.75 x 10²⁵ molecules H₂O will react with (?) atoms of Na.

Same procedure, convert to moles, solve problem by ratios then convert to needed dimension at end of problem.

                         Na          +            H₂O                                   =>           NaOH           +    H₂

Given:           excess            2.75 x 10²⁵ molecules H₂O    =>      ? atoms NaOH       ----

Convert to moles =>          2.75 x 10²⁵ molecules H₂O / 6.023 x 10²³ molecules H₂O/mole H₂O  

                                             = 45.658 moles H₂O              =>  45.658 moles NaOH  (coefficients are equal)

Convert moles NaOH to grams NaOH                            =>   45.658 moles NaOH x  40 grams NaOH/mole NaOH

                                                                                                     = 1826.33 grams NaOH  

Master the mole concept and you master a lot of chemistry! Good luck.

Answer: 4. We know that one mole of any chemical compound always contains 6.022 x 10^23 molecules. Therefore, we can calculate the number of molecules of 2.25 moles of sulfur dioxide SO2 by multiplying the number of moles by the Avogadro's constant 6.022 x 10^23:    

    2.25 moles SO2 (6.022x10^23 molecules/1mole) = 1.355 x 10^24 molecules of sulfur dioxide

5. The number of moles of sodium chloride are 0.40 moles

Explanation:

Answer:

T₂ = 478.93 K

Explanation:

Given that,

Initial pressure, P₁ = 178 kPa

Initial temperature, T₁ = 37°C = 310 K

Final pressure, P₂ = 275 kPa

We need to find the new temp of the air in the tire, assuming the volume is constant. We know that,

[tex]\dfrac{P_1}{T_1}=\dfrac{P_2}{T_2}\\\\T_2=\dfrac{P_2T_1}{P_1}\\\\T_2=\dfrac{275\times 310}{178}\\\\T_2=478.93 K[/tex]

So, the new temperature is equal to 478.93 K.

Answer:

15Hz

Explanation:

75m/s / 5m = 15Hz

I hope this helps u! :D

Answer: 15?

Explanation: You take the formula of velocity=length/frequency and change it to velocity/length=frequency to accommodate the values you have.