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Answer:A force is a push or pull upon an object resulting from the object's interaction with another object.

A force acting on an object causes the object to change its shape or size, to start moving, to stop moving, to accelerate or decelerate

Answer:

Yes, it is correct.

Explanation:

400 cm = 4 m

40 m = 40 m

0.4 km = 400m

Therefore, 400 cm < 40 m < 0.4 km

Answer:

Explanation:

400 centimeter....... smallest

0.4 kilometer .............. middlest

40 meter..................... greatest

Answer: C

Explanation: The atomic number is fixed by the number of protons. An element will have an exact number of protons. The neutrons can vary, and they are the reason elements have isotopes (all the same number of protons, but some have differing numbers of neutrons). Electrons are too small to be counted in the atomic weight figures.

Answer:

molecular weight of Phosphorus Pentachloride or grams The molecular formula for Phosphorus Pentachloride is PCl5. The SI base unit for amount of substance is the mole. 1 mole is equal to 1 moles Phosphorus Pentachloride, or 208.238761 grams.

Explanation:

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Answer:  3.156 grams

Explanation:  The additional volume is 4 ml.  (0.789 g/ml)*(4 ml) = 3.156 grams

Answer:

+27 66 514 3800

Explanation:

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Answer:

D

Explanation:

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Producing hydrogen gas. Hence, option D is correct.

Electrolysis is described by two half-reactions. These half reaction are the oxidation half-reaction and reduction half-reaction.

Electrolysis involves the transfer of electrons. Each half reaction is characterized by the loss or gain of electrons.

The only reason why producing hydrogen gas is not used most of the time is because electrolysis has very low efficiency, most of the energy finishes up being converted to heat and 95% of the hydrogen is produced by steam reforming.

Hence, option D is correct.

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Answer:

Mass/Volume

Explanation:

Answer:

[tex]{ \sf{density = \frac{mass}{volume} }}[/tex]

Answer:

10,000,000

Explanation:

45000÷0.0044

=10,000,000

Answer:

10,000,000 times larger.

Explanation:

Multiply 0.0045 by 10,000,000 to get 45000. Or, Divide 45000 by 0.0045 to get 10,000,000.

Answer:

Answer is in the attachment

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Explanation:

oxygen (O)will react with water(H2O) to form hydroxide which is (OH

Answer: B. Compare the similarities of the climate in Ireland with the climate in Greenland.

We should Compare the similarities of the climate in Ireland with the climate in Greenland.

Answer:  Exothermic

Explanation:  The energy of the reactants is leass than that of the products.  Conservation of energy means that the excess is given off, or exothermic.

Answer:

the elements are listed in order of increasing atomic number. The atomic number is the number of protons in the nucleus of an atom.In a periodic table arranged in order of increasing atomic number, elements having similar chemical properties naturally line up in the same column.

The elements on the periodic table are arranged on the basis of highlighting similarities between elements. Thus, the correct option for this question is A.

The elements on the periodic table are basically arranged on the basis of increasing their atomic number. These atomic number is represented by the number of protons in the nucleus of an element.

According to the question, the elements possessing identical chemical properties are arranged in the same group. For example, group 17 is known as the halogen group. Among this group, the elements bear one electron short to fulfill their octet.

The whole periodic table comprises of 18 groups and 7 periods.

Therefore, the elements on the periodic table are arranged on the basis of highlighting similarities between elements. Thus, the correct option for this question is A.

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When conducting research, scientists use the scientific method to collect measurable, empirical evidence in an experiment related to a hypothesis (often in the form of an if/then statement), the results aiming to support or contradict a theory.

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Answer:The below file contains the answer

Explanation:

Answer:

0.162 mol

Explanation:

n=m/M

M= 20*3 + 15*2 + 8*4*2

M=154 g/mol

n=25g/154g/mol

n=0.162 mol

The number of moles in 25 grams of calcium phosphate is 0.162 mol.

Mole is a SI unit that is used to measure the quantity of any substance in a specific amount. To calculate the moles, we will divide the mass of the substance by the molar mass of that substance.

n = m/M

Calcium phosphate is a chemical compound that contains calcium and phosphorus or phosphoric acid, and it is used to treat the low calcium in the body and thyroid and parathyroid.

The molar mass of calcium sulfate is 154 g/mol

The mass of calcium sulfate is 25 grams

Putting the value in the equation

n = m/M

n = 25g / 154 g/mol = 0.162 mol

Thus, the moles of calcium sulfate are 0.162 mol.

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Answer:

7. 1200×23.4=28080

9. = 78.512

10. =341.199

11= 7.45

12 =65.0023

13.=3400210.34

Explanation:

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Answer:

Explanation:

It is a colorless liquid. It reacts with water to give adipic acid. It is prepared by treatment of adipic acid with thionyl chloride.

Adipoyl Chloride can be used in the synthesis of nylon. Also it is used in the synthesis of chiral polymer for membrane application.

Answer:

It is 0.05 moles of water

Explanation:

From avogadro's number:

[tex]{ \sf{6.02 \times {10}^{23} \: mole cules= 1 \: mole }} \\ { \sf{3 \times {10}^{22} \: molecules = ( \frac{3 \times {10}^{22} }{6.02 \times {10}^{23} }) \: moles }} \\ \\ { \sf{ = 0.05 \: moles}}[/tex]

Answer:

[tex]\boxed {\boxed {\sf 0.05 \ mol \ H_2O}}[/tex]

Explanation:

We are asked to calculate the number of moles of water, given the molecules of water.

We will convert moles to molecules using Avogadro's Number or 6.022 × 10²³. This is the number of particles (atoms, molecules, formula units, etc.) in 1 mole of a substance. In this case, the particles are molecules of water or H₂O.

We will convert using dimensional analysis, so we must set up a ratio using Avogadro's Number.

[tex]\frac {6.022 \times 10^{23} \ molecules \ H_2O} { 1 \ mol \ H_2O}[/tex]

We are converting 3 × 10²² molecules of water to moles, so we must multiply the ratio by this value.

[tex]3 \times 10^{22} \ molecules \ H_2O*\frac {6.022 \times 10^{23} \ molecules \ H_2O} { 1 \ mol \ H_2O}[/tex]

Flip the ratio so the units of molecules of water cancel.

[tex]3 \times 10^{22} \ molecules \ H_2O*\frac{ 1 \ mol \ H_2O} {6.022 \times 10^{23} \ molecules \ H_2O}[/tex]

[tex]3 \times 10^{22} *\frac{ 1 \ mol \ H_2O} {6.022 \times 10^{23}}[/tex]

[tex]\frac {3 \times 10^{22}} {6.022 \times 10^{23}} \ mol \ H_2O[/tex]

[tex]0.04981733643 \ mol \ H_2O[/tex]

The original value of molecules of water ( 3 × 10²² ) has 1 significant figure, so our answer must have the same number of sig figs. For our answer that is the hundredth place. The 9 in the thousandth place tells us to round the 4 in the hundredth place up to a 5.

[tex]0.05 \ mol \ H_2O[/tex]

3×10²² molecules of water are equal to 0.05 moles of water.

Answer:

[tex]\boxed {\boxed {\sf 82.7 \textdegree C}}[/tex]

Explanation:

We are asked to find the temperature of a gas given a change in pressure and volume. We will use the Combined Gas Law, which combines 3 gas laws: Boyle's, Charles's, and Gay-Lussac's.

[tex]\frac {P_1V_1}{T_1}=\frac{P_2V_2}{T_2}[/tex]

Initially, the gas has a pressure of 1.05 atmospheres, a volume of 4.25 cubic meters, and a temperature of 95.0 degrees Celsius.

[tex]\frac {1.05 \ atm * 4.25 \ m^3}{95.0 \textdegree C}= \frac{P_2V_2}{T_2}[/tex]

Then, the pressure increases to 1.58 atmospheres and the volume decreases to 2.46 cubic meters.

[tex]\frac {1.05 \ atm * 4.25 \ m^3}{95.0 \textdegree C}= \frac{1.58 \ atm *2.46 \ m^3}{T_2}[/tex]

We are solving for the new temperature, so we must isolate the variable T₂. Cross multiply. Multiply the first numerator by the second denominator, then multiply the first denominator by the second numerator.

[tex](1.05 \ atm * 4.25 \ m^3) * T_2 = (95.0 \textdegree C)*(1.58 \ atm * 2.46 \ m^3)[/tex]

Now the variable is being multiplied by (1.05 atm * 4.25 m³). The inverse operation of multiplication is division, so we divide both sides by this value.

[tex]\frac {(1.05 \ atm * 4.25 \ m^3) * T_2}{(1.05 \ atm * 4.25 \ m^3)} = \frac{(95.0 \textdegree C)*(1.58 \ atm * 2.46 \ m^3)}{(1.05 \ atm * 4.25 \ m^3)}[/tex]

[tex]T_2=\frac{(95.0 \textdegree C)*(1.58 \ atm * 2.46 \ m^3)}{(1.05 \ atm * 4.25 \ m^3)}[/tex]

The units of atmospheres and cubic meters cancel.

[tex]T_2=\frac{(95.0 \textdegree C)*(1.58* 2.46 )}{(1.05 * 4.25 )}[/tex]

Solve inside the parentheses.

[tex]T_2= \frac{(95.0 \textdegree C)*3.8868}{4.4625}[/tex]

[tex]T_2= \frac{369.246}{4.4625} \textdegree C}[/tex]

[tex]T_2 = 82.74420168 \textdegree C[/tex]

The original values of volume, temperature, and pressure all have 3 significant figures, so our answer must have the same. For the number we calculated, that is the tenths place. The 4 in the hundredth place to the right tells us to leave the 7 in the tenths place.

[tex]T_2 \approx 82.7 \textdegree C[/tex]

The temperature is approximately 82.7 degrees Celsius.

Answer:5600 years

Explanation:

the amount of time it takes for the quantity to lose 50% (Half life) of its value. The half-life of carbon-14 is about 5600 years. Thus, after 5600 years, a piece of cotton cloth will contain half the carbon-14 that was in the original cotton plant.

Answer: theo mình thì mình làm như sau

cu(no3)2 nhiệt phân hết

\Rightarrow nNO2= 0,02mol

nO2=0,005mol

khi hấp thụ O2 và NO2 vào nước ta có

2NO2 + 1/2 O2\Rightarrow 2HNO3

phản ứng là vừa đủ nên

nHNo3= 0,02 mol

pH HNO3=2

khi cho 0,001mol NaOH vào thì phản ứng trung hòa

H+ + OH- \Rightarrow H20

nHNO3=0,02/20=0,001

nhận thấy nH+ =nOH- nên phản ứng vừa đủ

pH của dd Y=7

theo mình giải là như vậy

Explanation:

Answer:

Copper is less reactive than hydrogen, so copper (Cu) is produced at the negative electrode. The half equation is: Cu2+ + 2e- → Cu

The hydroxide ion is more reactive than the sulphate ion, therefore this forms water (H2O) and oxygen at the positive electrode.

Answer:

In his 1805 work, "A New System of Chemical Philosophy," Dalton propounded the tenets of his atomic theory: The chemical elements are made of atoms. The atoms of an element are identical in mass. Atoms of different elements have different masses.

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Answer:

the answer is the number of gas molecules changes.

Answer:

density = (mass) divided by (volume)

or just D = M/V

Answer:

407.5 g

Explanation:

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