Answers
Answer:
answers:
1.b
2.d
3.b
4. c
5.c
6.d
7.c
Explanation:
I think this is the correct answer pls mark brainliest and like..
19. place moth balls in the closet and observe after several days.
20. whenever wax or a candle burns it turns from solid to liquid but again at room temperature it turns to solid
21. evaporation, condensation, precipitation
22. it produces new substances
23. vinegar Bubbles when baking soda is added.
24. steam
Related Questions
(Please Help)
1.What is the most common isotope for element X
2.Calculate the average atomic mass or element X
Answers
Answer:
1. Isotope 2 occurs most commonly
2. 39.02amu
Explanation:
1. Isotope 2 has a relative abundance of 78.68% i.e. 78.68 out of 100, hence, it is the isotope that occurs most commonly.
2. Isotope 1 = 9.67%, mass no: 38
Isotope 2 = 78.68%, mass no: 39
Isotope 3 = 11.34%, mass no: 40
Isotope 4 = 0.31%, mass no: 41
To find the average atomic mass of element X, we multiply each isotopes' relative abundance by its mass no and find the sum as follows:
We convert each percentage to decimal abundance:
Isotope 1 = 9.67% = 0.0967
Isotope 2 = 78.68% = 0.7868
Isotope 3 = 11.34% = 0.1134
Isotope 4 = 0.31% = 0.0031
(0.0967 × 38) + (0.7868 × 39) + (0.1134 × 40) + (0.0031 × 41)
3.6746 + 30.6852 + 4.536 + 0.1271
Average atomic mass = 39.02amu
a beam balance is called a first class lever why?
Answers
Answer:
A beam balance is an example of a first class lever.
Explanation:
A beam balance is an example of a first class lever. In a first class lever, the fulcrum is between the effort (force) and the load. The effort (force) moves over a large distance to move the load a smaller distance.
Other examples of first class lever are pliers, scissors, a crow bar, a claw hammer, a see-saw and a weighing balance etc.
In an electrically neutral atom, the number of
protons equals the number of neutrons.
protons equals the number of electrons.
neutrons equals the number of electrons.
A. Protons equals the number of neutrons
B. Protons equal the number of electrons
C. Neutrons equals the number of electrons
Answer: B
Answers
Answer:
B
Explanation:
because protons have a +1 charge and electrons have a -1 charge, so if an atom is neutral it must have the same amount of protons and neutrons
Which of the following numbers is equal to the value snow
notation below?
4.8 x 10^-4
A. 0.0048
ОО
B. 0.00048
C. 0.048
D. 0.000048
Answers
Answer:
B
Explanation:
4.8×10^-4
10^-4 = 0.0001
4.8×0.0001 = 0.00048
A heat lamp produces____
light.
Answers
Answer:
infrared light
Explanation:
Cuál es el cruce para un niño donde su padre tiene el pelo rizo RR y su madre pelo lacio rr
Answers
Answer:
Rr
Explanation:
What are the example of molecule ?
Answers
Explanation:
H2O water molecule
O3 Ozone
are some of common example of molecules
Calculate the numerical Kc value for the following reaction if the equilibrium mixture contains 0.51 M CO , 0.30 M H2 , 1.8 M CH4 , and 2.0 M H2O.
CO(g) + 3H2 (g) ⇌ CH4 (g) + H2O (g)
Show work
Answers
Answer:
uh i think this is the answer
Explanation:
Which of the following equalities is not correct?
a. 1 cm^3 = 1 mL
b. 1000 mm = 1 m
c. 100 cg = 1 g
d. 10 kg = 1 g
Answers
Answer:
a. 1 cm^3 = 1 mL
explanation:
C₂H₄O₂ + O₂ ➞ CO₂ + H₂O
Answers
Answer:
C2H4O2 + 2O2 ==> 2CO2 + 2H2O
Explanation:
Start with the carbons
C2H4O2 + O2 ==> 2CO2 + H2O There are 2 on the left, so you need 2 on the right.
Next deal with the hydrogens. You have 4 on the left so you have to make 4 on the right
C2H4O2 + O2 ==> 2CO2 + 2H2O
The oxygens are the real devil in this question. Be careful how you handle them. There are 2 * 2 = 4 from the CO2 and 2*1 = 2 from the water. The total is 6
Now you can't just put a 3 in front of the O2. There are 2 in the given chemical. So you don't need 6. You need 6 -2 = 4. But the oxygen is O2. You have to divide the 4 by 2 to get 2
C2H4O2 + 2O2 ==> 2CO2 + 2H2O
And that's your answer.
If the sky is actually black, and the water is actually clear, where does the blue color for the sky and water come from?
Answers
Answer:
that the water is blue because of the way water absorbs light, the way particles in the water scatter light, and also because some of the blue light from the sky is reflected
if you have a pop quiz and you get nervous is that unconditioned response? if yes why? if not what kind of response is it
Answers
What is the molarity of the solution formed by dissolving 80. G of NAOH(s) into water to give a total volume of 4.00 l
Answers
Answer:
0.5 M
Explanation:
From the question given above, the following data were obtained:
Mass of NaOH = 80 g
Volume of solution = 4 L
Molarity =?
Next, we shall determine the number of mole in 80 g of NaOH. This can be obtained as follow:
Mass of NaOH = 80 g
Molar mass of NaOH = 23 + 16 + 1
= 40 g/mol
Mole of NaOH =?
Mole = mass / molar mass
Mole of NaOH = 80 / 40
Mole of NaOH = 2 moles
Finally, we shall determine the molarity of the solution. This can be obtained as follow:
Mole of NaOH = 2 moles
Volume of solution = 4 L
Molarity =?
Molarity = mole / Volume
Molarity = 2/4
Molarity = 0.5 M
Therefore, the molarity of the solution is 0.5 M.
NEED AN ANSWER ASAP!!! PLSSS
Compare and contrast an electrolytic cell with a voltaic cell. Provide one example where both are present in daily life.
Answers
Answer:
In both voltaic and electrolytic cells, oxidation occurs at the anode, while reduction occurs at the cathode. Thus, both these cells exhibit redox reactions. In both these cells, electrons flow from the anode to the cathode through the externally connected conductor.
Answer:
ELECTROLYTIC CELL
An electrochemical cell in which a non-spontaneous chemical reaction takes place when electric current is passed through the solution,is called an electrolytic cell.
EXAMPLE
Nelsons cell and Downs cell
VOLTAIC CELL OR GALVANIC CELL
The electrochemical cell in which a spontaneous chemical reaction takes place and generates electric current is called galvanic and voltaic cell.
EXAMPLE
Daniel cell
Explanation:
In the past mining companies were not made responsible for the clean-up of any of the mine sites. As a result, abandoned mines had a severe impact on the environment in Ontario. Which of these is not a result of these mining practices?
1) Chemical reactions producing sulphuric acid decrease soil and water PH in the area.
2) Acid leaching dissolves metals found in the soil thus allowing them to enter the water system.
3) Heavy metals which are left tailing ponds can dissolve and enter the water system.
4) Old and inefficient mining smokestacks contaminate the soils around abandoned mine sites.
Answers
Answer:
Old and inefficient mining smokestacks contaminate the soils around abandoned mine sites.
Explanation:
A smokestack, is a very tall channel commonly used in many instances to release gases produced by combustion processes directly into the air. These high towers are aimed at dispersing the gaseous pollutants over a wider area thereby minimizing their impact.
Old and inefficient smokestack do not contaminate the soil since they are very high towers that discharge gases directly into the atmosphere. Hence they are not part of the sources of soil contamination in abandoned mines.
Which is a constructive process? Rivers carrying sediment down stream, the rusting of a bridge, waves cutting back a beach front, volcanic eruption caused by plate tectonics
Answers
Answer:
volcanic eruption caused by plate tectonics.
Explanation:
Constructive process is one in which memories are influenced by some events. When a person tries to retrieve the memory he first click some event which is associated with that memory and then whole flash backs comes to his mind.
1.25 X 10^24 molecules of chlorine gas react with sodium to form how many grams of sodium
chloride?
2Na + Cl2
--> 2NaCl
Answers
Answer:
241.28 g NaCl(s)
Explanation:
Given 1.25 x 10²⁴ molecules of Cl₂ = 1.25 x 10²⁴molecules Cl₂(g)/6.023 x 10²³ molecules/mole = 2.08 mole Cl₂(g)
2Na(s) + Cl₂(g) => 2NaCl(s)
excess 2.08mole ? mole
∴moles NaCl(s) formed from 2.08 moles Cl₂(g) = 2(2.08 mole NaCl(s))
= 4.16 mole NaCl(g) = 4.16 mole NaCl(s) x 58 g NaCl(s)/mole NaCl(s) = 241.28 g NaCl(s)
which of the following pairs are ionic compounds ( Al,Cl),(Na,O),(Al,F)
Answers
Answer:
This answer I think it is Al,F
need help asap!!!
so i don’t necessarily need an answer just how to solve everything.
this is the first one:
calcium hydroxide + ammonium chloride
the instructions are attached to this question. i’m just not sure how to do everything. it doesn’t give me the products side only the reactants so how am i supposed to write and balance the equation?
Answers
Explanation:
とおふぉくぉをえおろとようおいおぽあおそ・
'」*とまっぉのもヴぉこぉぞぽ、こ、
Answer:
Ca(OH)2 + 2NH4Cl .................. CaCl2 + 2NH3 + 2H2O
Which of the following statements about the nucleus is false?
A. Contains nearly all of the mass of the atom.
B. Able to be lost or gained in chemical reactions.
C. None of these
D. Made up of protons and neutrons
Answers
Answer:
B. Able to be lost or gained in chemical reactions.
Answer:
B
Explanation:
a chemical reaction would only move the nucleas
If calcium carbonate (Cacos) decomposes. What would the product of the reaction be?
Answers
Answer:
CaO
Explanation:
Group 2 Carbonates decompose to form oxides of the Group 2 element and Carbon dioxide
Because electrons are orbiting the nucleus, the nucleus is stationary
true or false
Answers
Answer:
false, The nucleus of atoms still move around like crazy, it's just the electrons move more.
Polywool fibre is
a.natural
b.synthetic
c.monomer
d.blended
Answers
Polywool fibre is synthetic.
⇒b. Synthetic
Hope It Helps You ✌️
Answer:
[tex]\large{\underbrace{\underline{\fcolorbox{White}{pink}{\bf{b.synthetic }}}}}
[/tex]
Give reasons: a) Cocoons are boiled in hot water. b) Camel wool considered a natural health product.
Answers
Answer:
•cocoons are boiled in hot water for obtaining silk fibres from cocoons.
•camel wool considered a natural health product because it has excellent thermal proities
calculate the final pressure of a gas that is expanded from 725cm³ at 30C and 1.19 atm to 1.12cm³ at 43C
Answers
Answer:
Final pressure, P2 = 1088.89 atm
Explanation:
Given the following data;
Initial volume, V1 = 725 cm³
Initial temperature, T1 = 30°C
Initial pressure, P1 = 1.19 atm
Final volume, V2 = 1.12 cm³
Final temperature, T2 = 43°C
To find the final pressure (P2), we would use the combined gas law.
Mathematically, the combined gas law is given by the formula;
[tex] \frac {PV}{T} = k [/tex]
[tex] \frac {P_{1}V_{1}}{T_{1}} = \frac {P_{2}V_{2}}{T_{2}} [/tex]
Substituting into the formula, we have;
[tex] \frac {1.19*715}{30} = \frac {P_{2}*1.12}{43} [/tex]
[tex] \frac {850.85}{30} = \frac {P_{2}*1.12}{43} [/tex]
[tex] 28.3617 = \frac {P_{2}*1.12}{43} [/tex]
Cross-multiplying, we have;
[tex] 28.3617 * 43 = 1.12P_{2} [/tex]
[tex] 1219.5531 = 1.12P_{2} [/tex]
[tex] P_{2} = \frac {1219.5531}{1.12} [/tex]
Final pressure, P2 = 1088.89 atm
cuantos gramos y moleculas de dioxido de carbono hay en 0.5 moles de dioxido de carbono
paso a paso
Answers
Answer:
metro= 22g
Explanation:
3. How many moles are present in 100 g of Ca(NO3)2?
PLEASEEE HELP ASAPP
Answers
0Answer: 0.6094
Explanation:
no of moles = mass / molar mass = 100/164.088= 0.6094 mole
Answer:
0.609 moles
Explanation:
mass in g ÷ atomic mass = moles
Ca(NO₃)₂ = 1 Ca 40.078 amu
2 N 28.0134 amu
+ 6 O 95.994 amu
____________________
164.0854 amu
100 g ÷ 164.0854 amu = 0.609 moles
three significant digits
If you produce 35.7 grams of sodium chloride how many molecules of Chlorine gas were
needed?
2Na + Cl2 --> 2NaCl
(PLS HELP ASAP)
Answers
Explanation:
I did it in steps to help u to understand :)
The nonmetals include which of the following groups? Use the periodic table to answer the question. Check all that apply.
halogens
alkali metals
lanthanides
noble gases
alkaline earth metals
Answers
Answer:
En el grupo de los no metales se incluyen los halógenos (flúor, cloro, bromo, yodo, astato y téneso), que tienen 7 electrones en su última capa de valencia y los gases nobles (helio, neón, argón, kriptón, xenón, radón), que tienen 8 electrones en su última capa (excepto el helio, que tiene 2).
Explanation:
halógenos
Answer:
1,4
Explanation:
Cuando se quema 1 mol de metano –o sea, 16 g–, se desprenden 802
kJ/mol.
○ Cuando se quema 1 mol de octano –o sea, 114 g–, se desprenden 5500
kJ/mol.
Pareciera que el octano puede brindar más energía al quemarse, pero vamos a
hacer un análisis más cuidadoso. Comparemos la combustión de igual masa de
cada combustible.
● Calculen la cantidad de calor que se desprende cuando se quema un gramo
de cada combustible.
1 gr de metano aporta……………………………
1 gr de octano aporta………………………………
Answers
Answer:
1 gramo de metano aporta 50.125 kilojoules.
1 gramo de metano aporta 48.246 kilojoules.
Explanation:
La cantidad de energía liberada por la combustión de una unidad de masa del hidrocarburo ([tex]Q[/tex]), en kilojoules por mol, es igual a la cantidad de energía liberada por mol de compuesto ([tex]\bar {Q}[/tex]), en kilojoules por mol, dividido por su masa molar ([tex]M[/tex]), en gramos por mol:
[tex]Q = \frac{\bar Q}{M}[/tex] (1)
A continuación, analizamos cada caso:
Metano
[tex]Q = \frac{802\,\frac{kJ}{mol} }{16\,\frac{g}{mol} }[/tex]
[tex]Q = 50.125\,\frac{kJ}{g}[/tex]
1 gramo de metano aporta 50.125 kilojoules.
Octano
[tex]Q = \frac{5500\,\frac{kJ}{mol} }{114\,\frac{g}{mol} }[/tex]
[tex]Q = 48.246\,\frac{kJ}{mol}[/tex]
1 gramo de metano aporta 48.246 kilojoules.