Please help me thanks so much??!!.:;))..I will mark you:))

Answer:

Their moms and dads. ;)

Explanation:

Answer:

Hope this helps.

Explanation:

Convert from miles to kilometers (rounded to 2 decimals):

5.5 mi/h * 1.609 = 8.86 km/h

The student arrives at school in:

8.86 km ------------- 1 h

3.2 km ---------------- x  

x = 3.2 * 1 / 8.86  

x = 0.3611 hours

Explanation:

kinetic energy is the energy an object has while in motion, if I'm walking I have kinetic energy

Answer:

Kinetix energy: of an object is the energy that it possesses due to its motion. ( nvm sorry youre working on chemistry)

Answer:

25.8 g C6H12O6

Explanation:

Answer:

MgBr(aq) + (NH4)3PO4(aq) -------> NH4Br(aq) + Mg3(PO4)2(s)

Explanation:

Answer:

Its temperature

Explanation:

if the cold air wants to move to the hot air, then that means its trying toequal out t=both the temperatures. meaning that the cold air will get hotter and the hot were ill get colder.

Temperature can be used to indicate which direction heat transfer will flow between two objects. The correct option is C.

Temperature is the measurement entity of the hotness and coldness of any object or body. Its SI unit is kelvin or Celsius. The heat always transfers from the hot body to the cold body.

The heat is always transferred from high temperature to cold temperature. Heat is warmness that is caused by the thermal energy of the body when kinetic energy or potential energy is converted into thermal energy.

In a closed system, the energy is transferred by the means of heat and work. Otherwise, a closed system saves energy. The energy is transferred always within the same boundaries.

Thus, the correct option is C. Temperature.

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Answer:

atomic number of phosphorous is 15. It has zero charges because it has equal number of protons and electrons

Explanation:

The given question is an incomplete question, the complete question is given below.

Use this equation to answer the questions that follow.

[tex]3O_2(g)+N_2(g)\rightarrow 2NO_3(g)[/tex]

5 moles of oxygen gas are present. How many moles of [tex]NO_3[/tex] will be produced with this amount of oxygen gas?

Answer : The moles of [tex]NO_3[/tex] produced will be 3.33 moles.

Explanation : Given,

Moles of oxygen gas = 5 moles

Now we have to calculate the moles of [tex]NO_3[/tex].

The given balanced chemical equation is:

[tex]3O_2(g)+N_2(g)\rightarrow 2NO_3(g)[/tex]

From the balanced chemical equation we conclude that,

As, 3 moles of [tex]O_2[/tex] gas react to produces 2 moles of [tex]NO_3[/tex] gas

So, 5 moles of [tex]O_2[/tex] gas react to produces [tex]\frac{2}{3}\times 5=3.33[/tex] moles of [tex]NO_3[/tex] gas

Therefore, the moles of [tex]NO_3[/tex] produced will be 3.33 moles.

Answer:784.532 newton

Explanation:

An element is a distinct substance that cannot be split - up into simpler substances. Such substances consist of only one kind of atom.

From the list, the elements are:

helium

aluminum

A compound is substance composed of two or more kinds of atoms or elements joined together in a definite grouping. The properties of a compound are distinct and different from those of the individual elements that are combined in its make - up.

methane

water

Table sugar

A mixture is a substance made up of indefinite composition. The constituents reacts differently to changed conditions. They are easily separated into constituents by physical methods.

Vinegar

Steel

Milk

Answer:

1) Mass =  890.96 g

2) Mass =  7.67 g

3) 507.65 ×10²³ atoms

Explanation:

1) Given data:

Number of moles of lead = 4.3×10⁻³ mol

Mass of lead = ?

Solution:

Mass = number of moles × molar mass

Molar mass of lead = 207.2 g/mol

by putting values,

Mass = 4.3×10⁻³ mol × 207.2 g/mol

Mass =  890.96 g

2) Given data:

Number of atoms of antimony = 3.8×10²² atoms

Mass of antimony = ?

Solution:

1 mole contain 6.022 ×10²³ atoms

3.8×10²² atoms × 1 mol / 6.022 ×10²³ atoms

0.63×10⁻¹ mol

0.063 mol

Mass:

Mass = number of moles × molar mass

Molar mass of lead = 121.76 g/mol

Mass = 0.063 mol ×  121.76 g/mol

Mass =  7.67 g

3) Given data:

Mass of tungsten = 15.5 Kg (15.5 kg × 1000 g/ 1kg = 15500 g)

Number of atoms = ?

Solution:

Number of moles of tungsten:

Number of moles = mass/molar mass

Number of moles = 15500 g / 183.84 g/mol

Number of moles = 84.3 mol

1 mole contain 6.022 ×10²³ atoms

84.3 mol  × 6.022 ×10²³ atoms / 1mol

507.65 ×10²³ atoms

1. 9.36 moles S

2. 0.213 moles Al

Given

Reaction

2Al+3S⇒Al₂S₃

Required

moles of S

moles of Al

Solution

The reaction coefficient in a chemical equation shows the mole ratio of the compounds involved in the reaction (reactants or products)

From equation, mol ratio of Al₂S₃ : S = 1 : 3, so mol S :

= 3/1 x mol Al₂S₃

= 3/1 x 3.12

= 9.36 moles S

From equation, mol ratio of Al : S = 2 : 3, so mol Al :

= 2/3 x mol S

= 2/3 x 0.32

= 0.213 moles Al

Answer:

Explanation:

ok if yes do follow

Answer:

0.5050g of KHP were titrated

Explanation:

... (molar mass = 204.22 g/mol) has one acidic hydrogen. What mass of KHP was titrated (reacted completely) by the sodium hydroxide solution?

The KHP is a salt used as standard to determine concentrations of bases as NaOH solutions. The reaction that occurs is:

KHP + NaOH → KP⁻Na⁺ + H₂O

Only 1 hydrogen is acidic. Only 1 hydrogen reacts with NaOH

In the reaction you can see that 1 mole of NaOH reacts per mole of KHP

To find mass of KHP we need to determine its moles finding moles of NaOH (The moles of KHP required to reach endpoint = Moles of NaOH added):

Moles NaOH:

21.30mL = 0.02130L * (0.1161mol / L) = 0.002473 moles of NaOH = Moles KPH

With mass of KHP and its molar mass we can solve the mass of KHP:

0.002473 moles of KHP * (204.22g/mol) =

Answer:

2.force

Explanation:

Answer:

8.1g

0.1g

Explanation:

The reaction expression is given as:

      Fe   +   2HBr   →  FeBr₂    +    H₂

Mass of pure iron given  = 2.8g

A. Mass of HBr needed to dissolve a padlock of the mass;

To solve this problem, we need to use the mole concept.

 Convert mass of the known iron to the number of moles.

  Number of moles = [tex]\frac{mass}{molar mass}[/tex]  

  Molar mass  = 56g/mol  

   Number of moles of iron  = [tex]\frac{2.8}{56}[/tex]   = 0.05mole

 1 mole of Fe will react with 2 mole of HBr

 0.05mole of Fe will react with 0.05 x 2  = 0.1mole of HBr

 Mass of HBr  = number of moles x molar mass

   Molar mass of HBr  = 1 + 80   =  81g/mol

 Mass of HBr  = 0.1 x 81  = 8.1g

B. What mass of H2 would be produced by the complete reaction of the iron bar

    Since:

         1 mole of Fe will produce 2 mole of hydrogen gas

        0.05mole of Fe will produce 2 x 0.05mole  = 0.1mole of hydrogen gas

 Mass of hydrogen gas  = number of moles x molar mass

                                          = 0.1 x 1

                                          = 0.1g

Answer:

2)Both the salt dissolving and the evaporation of water are physical changes.

Explanation:

The two kinds of changes that has occurred are both physical changes.

Dissolution of a solute such as salt in water and evaporation of water from a solution are physical changes.

A physical change is one in which the physical property of matter is altered. Particularly the state and the form.

In many of these cases, the change is easily reversible.

Since this change is reversible in that we were able to collect the salt back, this is a physical change.

Answer:  It is more difficult to remove a valence electron from a Chlorine (Cl) atom

Explanation:

Ionization energy is the energy required to remove the valence electron from an isolated gaseous atom.

Magnesium (Mg) is the 12th element of periodic table and has an atomic number of 12. The electronic configuration is 2, 8, 2. It can easily lose its valence 2 electrons to attain stable configuration.

Chlorine (Cl) is the 17th element of periodic table and has an atomic number of 17. The electronic configuration is 2, 8, 7. It has a tendency to gain electron to attain stable configuration. It cannot lose its valence electron easily as the valence electrons experience more nuclear charge.

Thus it is more difficult to remove a valence electron from a Chlorine (Cl) atom

Chlorine(Cl) is the more difficult to remove a valence electron from which is

because it needs one electron to achieve a stable octet configuration.

Magnesium (Mg) is an element which has an atomic number of 12. The

electronic configuration is 2, 8, 2. This means it has to lose its  2 valence

electrons needed to attain a stable octet configuration.

Chlorine (Cl) is an element which has an atomic number of 17. The electronic

configuration is 2, 8, 7. This means it has to gain one valence electrons

needed to attain a stable octet configuration.

Thus it is more difficult to remove a valence electron from a Chlorine (Cl)

atom than Magnesium atom.

Read more on https://brainly.com/question/20714034

Based on the complete text, it is clear to see that the main point of the passage is A. Ultraviolet rays can cause chemical reactions.

This refers to the theme of a text that is used in order to show the message that an author wants to convey in a given text that he wants his readers to understand and grasp.

Hence, we can see that from the complete text which can be found on the official website of BBC news site, the story is told about the ultraviolet rays that were found to cause chemical reactions and discolored some parts of the paintings by Vincent Van Gogh,

This is further explained as the bright yellows in the paintings chemically reacted and thus turned into brown color and this shows that option A is the correct answer that shows the central idea or main point of the text.

Read more about central ideas here:

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Answer:

4 CO + 8 H2 -> 4 CH3OH

Hope that it works

Answer:

probably c i strongly agree with c

Explanation:

Answer:

I'm really not sure. my guess is the other person is probably right

Answer:

It would be thermal energy.

Explanation:

Thermal energy is the energy transfer of heat which is created while doing physical activity.

Answer:

6 protons

7 neutrons

protons is also the atomic number... and carbon is 6 on the periodic table. then just subtract the atomic number from the mass number.... then you get the number of neutrons

13-6= 7

Explanation:

Answer:

maybe 2455.2, good luck

Answer:Silica content influences magma behavior-____magmas have high silica content, are viscous (thick), and erupt at a lower temperature-____magmas have much lower silica content, more fluidlike behavior, and erupt at a higher temperature

Explanation:

Answer:

true

Explanation:

They explained it in the answer