help me pretty please

Answer:

A

Explanation:

the chemical energy in the phosphorous in the match turns into heat energy once the match is struck and starts to combust.

Answer:

Mg(s) + 2H⁺(aq) ⟶ Mg²⁺(aq) + H₂(g)  

Explanation:

A net ionic equation shows all the ionic substances as ions and shows the correct state of each substance.

Magnesium react with hydrochloric acid according to the equation :

This demonstration can be used to illustrate the characteristics reactions of metals with acid , a single replacement reaction ,or to demonstrate the generation of hydrogen gas.

Answer:

kidneys takes the waste out of the blood. It is then stored in the bladder, until the urinary tract takes the urine out of the body.

Answer:

0.0025moles

Explanation:

Molarity of a solution (M) = number of moles (n) ÷ volume (V)

According to this question, to make 250 mL of a 0.01 M solution of CaCl, the following number of moles is needed:

Volume = 250mL = 250/1000 = 0.250Litres.

Using; molarity = n/V

0.01 = n/0.250

n = 0.0025

n = 2.5 × 10^-3 moles.

Answer:

To use standard laboratory measurement devices to measure length, volume and mass amounts.

Answer:

False

Explanation:

Few organisms were not preserved as well as others, and new fossils are found every day

Answer:

v = 43.72 m/s

Explanation:

Given that,

Initial velocity of the train, u = 31 m/s

Acceleration of the train, a = 0.0705 m/s²

Time for which the train travel, t = 180.5 s

We need to find the final velocity of the train. Let it is v.. Using first equation of kinematics to find it such that,

[tex]v=u+at\\\\v=31+0.0705\times 180.5\\\\v=43.72\ m/s[/tex]

So the final speed of the train is equal to 43.72m/s.

Answer:

[tex]V_2=1099.35mL[/tex]

Explanation:

Hello there!

In this case, according to the given information, it is possible to infer that as both the amount of the gas and the pressure remains the same, we can solve this problem via the Charles' law a directly proportional relationship between the volume and temperature:

[tex]\frac{V_2}{T_2} =\frac{V_1}{T_1}[/tex]

Thus, by solving for the final volume, V2, we obtain:

[tex]V_2 =\frac{V_1T_2}{T_1} \\\\V_2 =\frac{886mL*371K}{299K}\\\\V_2=1099.35mL[/tex]

Best regards!

Answer:

brainly blurred the half of the question i cant read it completely

Explanation:

Answer:

B) go look on the periodic table for the atomic number

Explanation:

The atomic number is how many protons is in an atom

Answer:

Either A or B

Explanation: Because I learned it on Edge. :)

From the deepest ocean trench to the tallest mountain, plate tectonics explains the features and movement of Earth's surface in the present and the past.

Developed from the 1950s to the 1970s, the theory of plate tectonics is the modern update to continental drift, an idea first proposed by scientist Alfred Wegener in 1912 which stated that Earth’s continents had “drifted” across the planet over time. Wegener didn't have an explanation for how continents could move around the planet, but researchers do now: plate tectonics.  

Plate tectonics is the theory that Earth's outer shell is divided into large slabs of solid rock, called “plates,” that glide over Earth's mantle, the rocky inner layer above Earth’s core. Earth’s solid outer layer, which includes the crust and the uppermost mantle, is called the lithosphere. It is 100 km (60 miles) thick, according to the Encyclopaedia Britannica. Below the lithosphere is the asthenosphere—a viscous layer kept malleable by heat deep within the Earth. It lubricates the undersides of Earth's tectonic plates, allowing the lithosphere to move around.

Answer:

1. How fast do tectonic plates move? Answer: There are seven major plates: African, Antarctic, Eurasian, Indo-Australian, North American, Pacific and South American

2. What are the factors affecting plate tectonics? Answer: The force that causes most of the plate movement is thermal convection, where heat from the Earth's interior causes currents of hot rising magma and cooler sinking magma to flow, moving the plates of the crust along with them.

3. What 3 things support the theory of plate tectonics? Answer: Modern continents hold clues to their distant past. Evidence from fossils, glaciers, and complementary coastlines helps reveal how the plates once fit together. Fossils tell us when and where plants and animals once existed.

Explanation:

Hi there!

Here's a picture to show you. Does this help?

Answer:

350.7 g of NaCl

Explanation:

For this reactions our reactants are:

HCl and Na₂CO₃.

Then, the reaction is:

2HCl + Na₂CO₃ →  2NaCl  +  H₂CO₃

2 moles of hydrochloric acid react to 1 mol of sodium carbonate in order to produce 2 moles of salt and 1 mol of carbonic acid.

Ratio is 1:2. 1 mol of sodium carbonate can produce 2 moles of NaCl

Then, 3 moles of carbonate may produce (3 . 2) /1 = 6

We convert the moles to mass to determine the theoretical yield

6 mol . 58.45g /mol = 350.7 g

The theoretical yield of NaCl produced is 350.7 g.

NaCl is a salt, and it is an ionic compound.

The reaction is

[tex]\rm 2HCl + Na_2CO_3 \rightarrow 2NaCl + H_2CO_3[/tex]

2 mol of HCl reacts with 1 mol of [tex]Na_2CO_3[/tex] and produces 2 mol of NaCl and 1 mol of [tex]H_2CO_3[/tex].

The ratio will be [tex]Na_2CO_3[/tex] : NaCl

                                1 : 2

Then, for 3 mol of [tex]Na_2CO_3[/tex]

[tex]\dfrac{3 \times 2}{1} = 6[/tex]

Now, convert the moles to mass

[tex]6\; mol \times 58.45g /mol = 350.7 g[/tex]

Thus, the theoretical yield produced is 350.7 g.

Learn more about NaCl

https://brainly.com/question/1473063

Answer:

True

Explanation:

The answer to this question is true. The oxidizing flame is a flame which is gotten when oxygen is used excessively. The flame is bluish or almost purple in color. And it makes a hissing sound. The flame from this is shorter than the neutral flame. In the neutral flame there is neither the occurrence of oxidation or reduction.

Answer:

yea that's true

things you can do is: reduce ,reuse, and recycle

reduce the use of air/heat

remove lightbulbs and replace led bulb

drive less

plant a tree

Explanation:

Answer:

Teal

Explanation:

Blue lightens the cyan.

Answer:

it's b or d I am not 100% sure witch one tho

Answer:

B.

Explanation:

It is B because it says which is an example of A PHYSICAL MODEL. B is a physical model becuase by using tennis balls to represent the plantes (including the sun)

it is a model of a problem!!!

Have a great day!

Hope this helps!

-Lea

Answer:

it means 2 oxygen atoms in the molecule

Explanation:

Answer:

Fairly certain it's C. The particles In his hands vibrate faster because of friction :)

Answer:

C

Explanation:

Answer:

emission

Explanation:

when atoms return to lower energy levels they emit photons, in a process called emission

Given :

Temperature, T = 55° C = ( 55 + 273 ) K = 328 K .

Volume of container, V = 28.9 dm³ = 0.0289 m³ .

Pressure, P = 144 kPa = 144000 Pa .

To Find :

Number of moles of nitrogen  gas.

Solution :

We know, by ideal gas equation :

PV = nRT  ( R ( universal gas constant ) = 8.31 J K⁻¹ mol⁻¹ .

[tex]n = \dfrac{PV}{RT}\\\\n = \dfrac{144000\times 0.0289}{8.31 \times 328} \ moles\\\\n = \dfrac{4161.6}{2725.68}\\\\n = 1.53 \ moles[/tex]

Therefore, number of moles of nitrogen gas is 1.53 moles.

Answer:

F

parasite

Explanation:

Answer:

this should help

Explanation:

Answer:

Relation between , molality and temperature is as follows.

                T =

It is also known as depression between freezing point where, i is the Van't Hoff factor.

Let us assume that there is 100% dissociation. Hence, the value of i for these given species will be as follows.

         i for  = 3

          i for glucose = 1

          i for NaCl = 2

Depression in freezing point will have a negative sign. Therefore, d

depression in freezing point for the given species is as follows.

                 =

                  =

                   =

Therefore, we can conclude that given species are arranged according to their freezing point depression with the least depression first as follows.

                    Glucose < NaCl <

Explanation:

Answer:

92.26% of C

Explanation:

To solve this problem we must assume we have 1 mole of benzene. The mole contains 6 moles of C and 6 moles of H. We have to convert these moles to grams in order to find the total mass and mass percent will be:

Mass atom / Total mass * 100

Mass C: 6mol C * (12.0107g / mol) = 72.0642g

Mass H: 6mol H * (1.00794g / mol) = 6.04764g

total mass: 72.0642g + 6.04764g = 78.11184g

Mass percent of C will be:

72.0642g C / 78.11184g* 100

6.32 KJ is how much heat is given off