khan academy sucks. can someone answer this? :)

Answer:

There are three methods used to produce salt: solar, evaporation and rock mining.

Explanation:

Answer:

It can be brought into regular conversation easily I feel it means to "provoke" or "speeds significant change or action" I can see someone saying that in a conversation, "chlorine acts as a catalyst promoting the breakdown of ozone".

I would say it would take the same meaning depending on how you say it and when and what the context of what you're saying it in. 

For scientists, it means to change quickly. For someone who says it in a conversation may be saying to stop provoking someone. 

Explanation:

Answer:

See explanation

Explanation:

To convert from atm to mmHg

1 atm = 760 mmHg

0.799 atm = 0.799 atm * 760 mmHg/1 atm = 607.24 mmHg

To convert from atm to torr

1 atm = 760 torr

0.799 atm = 0.799 atm * 760 torr/1 atm = 607.24 torr

Answer:In regards to writing the formula, we know that magnesium has a charge of 1+ and sulfate, SO4, has a charge of 1-. Sulfate is a polyatomic ion so the charge of the whole thing is (SO4)1-. When you combine them you end up with MgSO4 and the "heptahydrate" is seven water molecules.

Explanation:

Answer:

Iduno sorry po hsjsnaka

Answer:

Don't touch radioactive waste with bare hands

Don't eat the radioactive thing

Wear protective eyewear

Wear lab coat/gloves

Explanation:

https://ehs.princeton.edu/laboratory-research/radiation-safety/radioactive-materials/handling-radioactive-materials-safely

Princeton article

Answer: The given statement is False.

Explanation:

Alpha particle is a helium nuclei.

Alpha particles are produced when a larger nuclei decays into smaller nuclei in radioactive decay. Alpha particles have mass number and atomic number as 4 and 2 respectively.

General representation of alpha decay :

[tex]^A_Z\textrm{X}\rightarrow ^{A-4}_{Z-2}\textrm{Y}+^4_2\textrm{He}[/tex]

Thus the given statement that alpha particle is composed of [tex]He^{2+}[/tex] ions is False.

The statement of [tex]\rm He^2^+[/tex] ions has formed the alpha particles is true.

Alpha particles are particles that have been similar to the He-4, with the presence of two protons and two neutrons. The alpha particles have the absence of electrons and have been formed during the alpha decay.

[tex]\rm He^2^+[/tex] has been the ion of He with the positive charge indicating the loss of 2 electrons. Thus, in [tex]\rm He^2^+[/tex], there has been 2 protons, 2 neutrons, and 0 electrons.

The atomic configuration of [tex]\rm He^2^+[/tex]has been similar to the alpha particles. Thus, the statement stating, "the alpha particles to be composed of [tex]\rm He^2^+[/tex]ions " is True.

For more information about the alpha particles, refer to the link:

https://brainly.com/question/1685421  

Answer:

9 moles

Explanation:

The balanced chemical equation for this decomposition reaction is as follows:

2KCIO3 → 2KCI+ 302

Based on this equation, 2 moles of potassium chlorate (KCIO3) decomposes to form 3 moles of oxygen gas (O2).

Hence, 6 moles of pottasium chlorate will decompose to produce;

6 × 3 ÷ 2

= 18 ÷ 2

= 9 moles of O2.

Answer:

I think D

Explanation:

it has both H and G in the planes.

Answer:

1. B. Ammonia and hexane will not dissolve because one molecule is polar and the other is non polar.

2. 1400 mL

Explanation:

In chemistry, like dissolve like! Ammonia is a polar molecule having a significant dipole moment owing to its three N-H bonds. On the other hand, hexane is a purely non-polar hydrocarbon hence the two substances can never dissolve in each other.

From the dilution formula;

C1V1=C2V2

C1= Initial concentration of the solution

V1 = Initial volume of the solution

C2 = Final concentration of the solution

V2= Final volume of the solution

2.8 M * 750.0 mL = 1.5 M * V2

V2 = 2.8 M * 750.0 mL/1.5 M

V2 = 1400 mL

Answer:

360g

Explanation:

Hope it helps you!

Answer:

*Metal= iron, copper, aluminium, lead, Mercury, zinc, chromium, Nickel, gold, silver, Platinum. *Non-metal= sulphur, oxygen, nitrogen, Phosphorus, hydrogen, chlorine, Silicon, Iodine.

Explanation:

Answer:

Metal!!!

Explanation:

Zinc is a chemical element with the symbol Zn and atomic number 30. Zinc is a slightly brittle metal at room temperature and has a blue-silvery appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodic table. Zinc (Zn), chemical element, a low-melting metal of Group 12 (IIb, or zinc group) of the periodic table, that is essential to life and is one of the most widely used metals. Zinc (Zn) is an abundant metal, found in the Earth's crust, with a myriad of industrial and biological uses. ... A base metal, zinc is primarily used to galvanize steel, a process that protects the metal against unwanted corrosion.

I uploaded the answer to a file hosting. Here's link:

tinyurl.com/wpazsebu

Answer: question 2 is (a) (25+273)k=298k(b) (373+273)k=646k

question 5 is 25 degree Celsius

question 1 is

a = (293-273) =20 degree Celsius

b = (470-273)=197 degree Celsius

question 3 is

a = naphthalene ball undergo sublimation due to which it convert directly into vapour and disappear into air without leaving any solid

b = the participle of perfume diffuse rapidly into air and its smell can be felt while sitting serval metre away

question 4 isthe force of allraction between the particles increases as we go from liquid to gas so the required order is : Oxygen< water< sugar

I hope it is helpful to you

Answer:

B

Explanation:

B, Hcl + NaoH = NaCl + H2O

Answer:

239.7mL

Explanation:

Using the general gas equation;

PV = nRT

Where;

P = pressure (atm)

V = volume (L)

n = number of moles (mol)

R = gas constant (0.0821 Latm/molK)

T = temperature (K)

The balanced chemical equation in this question is as follows:

CaC2(s) + 2H2O(l) --> Ca(OH)2(aq) + C2H2(g)

From the equation, 1 mole of CaC2 produces 1 mole of ethylene gas, C2H2.

Using mole = mass/molar mass

Molar mass of CaC2 = 40 + 12(2)

= 40 + 24

= 64g/mol

mole = 0.5487/64

mole = 0.00857mol of CaC2

Hence, 0.00857mol of CaC2 produced 0.00857mol of C2H2

Based on the information provided, n = 0.00857mol, T = 43°C = 43 + 273 = 316K, p = 0.926 atm

PV = nRT

V = nRT/P

V = 0.00857 × 0.0821 × 316/0.926

V = 0.222/0.926

V = 0.2397L

In mL, volume = 0.2397 × 1000

= 239.7mL

Molarity= no. of moles of solute/ volume of solution(in L)

Molarity = 6.2 moles/ 2.5 L = 62/25 mol/L

= 2.48 mol/L

The addition or subtraction of thermal energy. For example if you heat up an ice cube, it will melt to become water. If you heat it even more, it will evaporate.

Answer:

The element is in group 7, the halogens. The element is in the third period or row of the table.

Explanation:

Chlorine is element number 17.

Answer:

Here is the ANSWER KEY, it may also has other of the questions you don't know :)

Explanation:

https://sciencewithhorne.weebly.com/uploads/5/7/3/5/57358947/unit_11_hw_key.pdf

Answer:

Zinc mercury transition metal

Silicon boron metalloid

Oxygen nitrogen non metal

Sodium alkali metal

Explanation:

Answer:

Food and cell type

Explanation:

Kingdoms are by far the most basic legal structure for living objects. Living objects are classified into realms depending on how they consume food, the kinds of cells that produce their bodies, and the total type of tissue in their bodies.

Answer:

Oxygen mucury carbon dioxide and platinum

Explanation:

Answer:

from plants and animals.

Answer:

2802.5 KJ/mol

Explanation:

Calculate standard enthalpy of the Reaction :

6CO2(g) + 6H2O(l)C6H12O6 + 6O2(g)

using standard formation enthalpies . hence the standard enthalpy of the reaction = 2802.5 KJ/mol

attached below is the detailed solution

Answer:

1.The substance(s) to the left of the arrow in a chemical equation are called reactants. A reactant is a substance that is present at the start of a chemical reaction. The substance(s) to the right of the arrow are called products . A product is a substance that is present at the end of a chemical reaction.The combustion of methane or octane is exothermic; it releases energy. CH4 + 2 O2 → CO2 + 2 H2O + energy The energies of the products are lower than the energiies of the reactants.

Explanation:

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Answer:

The presence of a cell wall prevents the membrane from bursting,so cytolysis only occurs in animal and protozoa cells which do not have cell walls.

Explanation:

Answer:

3

Explanation:

Answer:

Their vibrating particles are packed together in relatively fixed positions.

Explanation:

As you can see in the image below, solid is packed together.