- Is energy absorbed or released by a material during the phase change from a solid to a liquid?

A)Absorbed
B)Released

Explanation:

Different heating process affect the microstructure of the steel in different ways. Thus, imparting different properties to the steel. For example, annealing is done is done to impart softness to steel, hardening is done to hardened the steel( eg: carburizing, nitriding, cyaniding) whereas tempering is done to improve the ductility of the steel.

Steel mainly contains iron and carbon. This percentage of carbon and iron decides the property of the steel. It is the % of carbon which is altered in different heating process that to obtained the desire microstructure in steel.

Answer:

Each time an excited helium atom falls back from an excited state to its ground state or to a lower energy state, it emits a photon of radiation that shows up as this specific line-emission spectrum.

Explanation:

Answer:

Mass over Volume........

Balanced equation :

2Al +6HCI⇒ 3H₂ + 2AlCI₃

Given

Reaction (unbalanced)

Al +HCI⇒ H₂ + ALCI₃

Required

Balanced equation

Solution

Give a coefficient

aAl +bHCI⇒ cH₂ + AlCI₃

Al, left = a, right=1⇒a= 1

Cl, left = b, right=3⇒b=3

H, left = b, right=2c⇒b=2c⇒3=2c⇒c=3/2

The equation becomes :

Al +3HCI⇒ 3/2H₂ + AlCI₃ x 2

2Al +6HCI⇒ 3H₂ + 2AlCI₃

Volume of solution : = 3083.3 ml = 3.0833 L

Given

a 6.0% w/v

185 g of glucose

Required

Volume of solution

Solution

% w/v : the mass of solute in a volume of solution or 1 g solute in 100 ml of solution

Can be formulated :

% w/v = (mass solute(g) : volume solution(ml)) x 100

Mass of solute = mass of glucose = 185 g

The volume of solution :

= 185 g : 0.06

= 3083.3 ml

= 3.0833 L

Answer:

it is option c liner eclipse

Answer:

A-It is a lunar eclipse, in which the Earth casts a shadow on the Moon.

Answer:

Mercury, Venus, Earth and Mars.

Explanation:

1. Find its coordination figure/coordination number of central atom (CF)

Ev = Vallence electron of central atom

Σe = electrons donated from substituents

Terminal O gives 0 electrons, hence Σe = 3 x 0

charge = charge of the compound

2. Find EP (electron pairs) and LP (lone pairs)

LP = CF - EP

3. Draw the skeleton with octet substituents (top right figure)

4. Find formal charge for each atoms (Qf)

5. Write formal charge near atom in skeleton

6. Enjoy

Answer:

c! Hope this helps!

Explanation:

BRAINLIEST PLZ ;)

Answer:

I think its the third one im not sure tho

Explanation:

Answer:

PRACTICE MULTIPLE CHOICE QUESTIONS FROM UNIT 10

1.) A cylinder is filled with 2.00 moles of nitrogen, 3.00 moles of argon, and 5.00 moles of helium. If

the gas mixture is at STP, what is the partial pressure of the argon?

(A) 152 torr (B) 228 torr (C) 380. torr (D) 760. torr

2.) Compared to the average kinetic energy of 1 mole of water at 0 oC, the average kinetic energy

of 1 mole of water at 298 K is

(A) the same, and the number of molecules is the same

(B) the same, but the number of molecules is greater

(C) greater, and the number of molecules is greater

(D) greater, but the number of molecules is the same

3.) If the pressure on a given mass of gas in a closed system is increased and the temperature

remains constant, the volume of the gas will

(A) decrease (B) increase (C) remain the same

4.) Which gas has approximately the same density as C2H6 at STP?

(A) NO (B) NH3 (C) H2S (D) SO2

5.) At a temperature of 273 K, a 400. milliliter gas sample has a pressure of 760. millimeters of

mercury. If the pressure is changed to 380. millimeters of mercury, at which temperature will

this gas sample have a volume of 551 milliliters?

(A) 100 K (B) 188 K (C) 273 K (D) 546 K

Get the answers to these questions

Back to the Unit 10 Old Tests Pag

Answer:

I'd say about 8?

Explanation:

if you wanna make them huge make about 6

Answer:

Pb₂O₄

Explanation:

The given species are:

        Pb⁴⁺               O²⁻  

Now, to solve this problem, we use the combining powers which corresponds to the number of electrons usually lost or gained or shared by atoms during the course of a chemical combination.

                                          Pb⁴⁺               O²⁻  

Combining power               4                    2

Exchange of valencies        2                    4

Now the molecular formula is  Pb₂O₄

Answer:

True

Explanation:

True is the ANSWER.

Answer:

23%

Explanation:

Answer:

There are three forces acting on the skateboard. One of these forces is the weight of the rider. Another is the force of gravity on the board itself. The third is the force of the ground pushing up on the skateboard.

Answer:

6

Explanation:

ye

Answer:

velocity and momentum

Explanation:

as you exert force, the object accelerates, hence, its velocity increases.

since momentum is mass times velocity, the momentum increases too

Please be reminded, this answer may not be 100% correct

When the force should be applied for a long time so it increases the change in velocity and momentum

The momentum of the object should be equivalent to the object mass times with the object velocity

Here

p = mv

Here p means momentum

m means mass

v means velocity

Here the momentum should be directly proportional to the mass of the object and for the velocity of the object also.

Learn more about mass here: https://brainly.com/question/1381544

Answer:

Examples of EM waves are radio waves, microwaves, infrared waves, X-rays, gamma rays, etc.

Answer:

Electromagnetic waves can be split into a range of frequencies. This is known as the electromagnetic spectrum. Examples of EM waves are radio waves, microwaves, infrared waves, X-rays, gamma rays, etc.

Explanation:

Answer:

45.9m

Explanation:

Given parameters:

Mass of the ball  = 1kg

Initial velocity  = 30m/s

Unknown:

Height the ball will travel  = ?

Solution:

At the maximum height, the final velocity of the ball  will be 0;

  Using ;

   V²   = U²   - 2gh

V is the final velocity

U is the initial velocity

g is the acceleration due to gravity

h is the height

     0² = 30²   - (2 x 9.8 x h)

    0 = 900 - 19.6h

      h  = 45.9m

Answer:

f = 0.94 ×10²⁴  Hz

Explanation:

Given data:

Frequency of light = ?

Wavelength of light = 3.2 ×10⁻¹⁶ m

Solution:

Formula:

Speed of light = wavelength × frequency

c = λ × f

c = speed of wave = 3×10⁸ m/s

by putting values,

3×10⁸ m/s  = f × 3.2 ×10⁻¹⁶ m

f  =  3×10⁸ m/s   / 3.2 ×10⁻¹⁶ m

f  = 0.94 ×10²⁴ s⁻¹

f = 0.94 ×10²⁴  Hz (Hz = s⁻¹)

Answer:B & C

tell me if im wrong

Answer:

Q 3 c it will reduce rate of photosynthesis in plants that live in the bottom of the lake

Q4 d the atom are in same group

This is right answer because these two elements are Lithium and neon Lithium is present in first group and Neon in last or group 18

Explanation:

Answer:

B D

Explanation:

hope this is right but not entirely sure

1.43 × 10⁻²⁰ mol Li

Math

Pre-Algebra

Order of Operations: BPEMDAS

Chemistry

Atomic Structure

Step 1: Define

8.63 × 10³ atoms Li

Step 2: Identify Conversions

Avogadro's Number

Step 3: Convert

Step 4: Check

Follow sig fig rules and round. We are given 3 sig figs.

1.43355 × 10⁻²⁰ mol Li ≈ 1.43 × 10⁻²⁰ mol Li

The heat of formation of nitrogen (II) oxide : +91.3 kJ/mol

Given

Reaction

N2(g) + O2(g) + 182.6 kJ → 2 NO(g)

Required

The heat of formation

Solution

In the above reaction, the heat of the reaction is located on the reactant side which indicates that the formation of nitric oxide requires heat (endothermic reaction).

In the above reaction the heat required to form 2 moles of NO, so the heat required for each mole is:

+182.6 kJ : 2 = =+91.3 kJ/mol

Answer:

B

Explanation:

scientists always look for evidence

Answer:

Yea its B

Explanation: The person above me legit toke the answer out of my mouth

Answer:

784.4kg

Explanation:

Given parameters:

Mass of Mg  = 200kg

Unknown:

Mass of MgCl₂  = ?

Solution:

  The reaction equation is given as:

            Mg  +  Cl₂ →   MgCl₂

Find the number of moles of the given specie;

  Number of moles of Mg = [tex]\frac{mass}{molar mass}[/tex]   = [tex]\frac{200000}{24.3}[/tex]   = 8230.5mole

So;

   1 mole of Mg will produce 1 mole of MgCl₂

   8230.5mole of Mg will produce 8230.5mole of MgCl₂

Mass of MgCl₂   = number of moles x molar mass

                    Molar mass of MgCl₂  = 24.3 + 2(35.5) = 95.3g/mol

 Mass of MgCl₂   = 8230.5mole x  95.3g/mol  = 784.4kg

Answer:

Heat packs that contain iron and water packets: Exposing the solution to air results in the oxidation of the iron (creates rust). The oxidation of the iron is an exothermic process. Heat packs that contain supersaturated sodium acetate: These are reusable, the packs are boiled to dissolve sodium acetate.

Explanation:Thanks for asking question