Answers
Related Questions
Which pair of elements are in the same period?Hg & PbLi & NaB & ClO & As
Answers
Answer:
Hg Pb are in one, Li and B and O are in one, and NaCl are in one, As is alone
Explanation:
Periods are horizontal
Hope this helps!
Astatine-218 has a half-life of 1.6 seconds. If you begin with a 1.7 g sample of astatine-218, how much of the sample remains after 3.2 seconds?
Answers
Answer:
do you still need help on this question
Explanation:
noble gases are used in many situations where a safe and constant environment must be maintained. for example, helium is used to provide a protective atmosphere for making fiber optics and semiconductors. argon is used to fill incandescent and flourescent light bulbs to prevent oxygen from corroding the hot filament. why are noble gases used in these situations?
Answers
Answer:
Noble gases have a complete valence electron shell making them stable and nonreactive.
Explanation:
What is the source of energy in nuclear weapons?
O A. Combustion
O B. Fusion
O C. Gravity
O D. Fission
Answers
Answer:
D. Fission
Explanation:
Induced fission is used to generate nuclear power and for weapons. The products formed during fission gain kinetic energy. It is this energy that is harnessed in nuclear power stations.
A student makes an aqueous solution of sodium hydroxide. Which statement correctly identifies the two ions present in the solute of this mixture?
The sodium ion is positive, and the hydroxide ion is negative.
The sodium ion is neutral, and the hydroxide ion is neutral
ОООО
The sodium ion is positive, and the hydroxide ion is
Answers
Answer:
PLEASE DO IT PROPERLY I WELL ANSWER IT BUT I CAN'T "I CANNOT UNDERSTAND" I'M VERY SORRY
Explanation:
Question:A student makes an aqueous solution of sodium hydroxide. Which statement correctly identifies the two ions present in the solute of this mixture?
A student makes an aqueous solution of sodium hydroxide. Which statement correctly identifies the two ions present in the solute of this mixture?The sodium ion is positive, and the hydroxide ion is negative.
A student makes an aqueous solution of sodium hydroxide. Which statement correctly identifies the two ions present in the solute of this mixture?The sodium ion is positive, and the hydroxide ion is negative.The sodium ion is neutral, and the hydroxide ion is neutral
A student makes an aqueous solution of sodium hydroxide. Which statement correctly identifies the two ions present in the solute of this mixture?The sodium ion is positive, and the hydroxide ion is negative.The sodium ion is neutral, and the hydroxide ion is neutralОООО
A student makes an aqueous solution of sodium hydroxide. Which statement correctly identifies the two ions present in the solute of this mixture?The sodium ion is positive, and the hydroxide ion is negative.The sodium ion is neutral, and the hydroxide ion is neutralООООThe sodium ion is positive, and the hydroxide ion is
Answer:The litmus paper test is a simple test in order to determine whether a given solution is acidic or basic. One will have to place a drop of a solution on the litmus paper. If it changes a red litmus paper to blue, the solution is basic. If it changes a blue litmus paper to red, the solution is acidic.
the are 2 answers
2nd² answer:It's because of 7-hydroxyphenoxazone. When exposed to acids below pH 4.5, the molecule looks like the image below and this gives litmus paper its red color. As the pH of the test solution moves towards alkaline, one of the hydrogen atoms (white hemispheres) starts to break off (disassociate).
CARRY ON LEARNING
THANKS FOR THE POINTS I HOPE YOU'LL UNDERSTAND ME.
P I E C K N P I E C K __________________someone pls help me explain this question
Question:
Temperature is a measure of how hot or cold something is.
Do you agree or disagree?
I need explanation I know its agree I just need to explain.
Answers
Answer:
yes agree. I is describing a feeling/ reaction to an action I hope this helps!:)
Silicone is a type of synthetic compound made of silicon, oxygen, and other elements. There are many different kinds of silicone. One kind is a liquid and is commonly used as a lubricant to reduce friction between moving parts. Unlike petroleum-based lubricants, silicone is nontoxic. However, silicone is more expensive than petroleum-based lubricants.
Which of the following would silicone lubricants most likely be used for?
Answers
Explanation:
Liquid-based lubricant
Answer:
study island : food service equipment
Explanation:
how does the number of valence electrons change as you move to the right across the periodic table?
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Answer:
The number of valence electrons goes up by one each time you move
Which statement describes one feature of Rutherford model of the atom
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[tex] \huge{ \color{magenta}{ \fcolorbox{magenta}{black}{ \huge{ \color{white}{ \fcolorbox{aqua}{black}{♡Answer♡ }}}}}}[/tex]
The Rutherford model shows that an atom is mostly empty space, with electrons orbiting a fixed, positively charged nucleus in set, predictable paths.
Why are the three atoms are isotopes of magnesium
Answers
Answer:
Magnesium is a naturally ubiquitous; (appearing & found evrywhere) element and has three naturally occurring stable isotopes, 24Mg, 25Mg and 26Mg, with relative abundance of 78.99%, 10.00% and 11.01%, respectively.
However, they differ only because a 24Mg atom has 12 neutrons in its nucleus, a 25Mg atom has 13 neutrons, and a 26Mg has 14 neutrons.
Explanation:
. A sample of ammonium phosphate can be prepared by the reaction of aqueous ammonia and phosphoric acid. 3NH3 (aq) + H3PO4 (aq) (NH4),PO4 (aq) 25.0cm of 1.25 mol/dm phosphoric acid is neutralised by 45.3cm of aqueou ammonia (a) Calculate the concentration in mol/dm3 of the ammonia used.
Answers
The concentration in mol/dm³ of the ammonia used is 2.07 mol/dm³
Balanced equation3NH₃ (aq) + H₃PO₄ (aq) -> (NH₄)₃PO₄ (aq)
From the balanced equation above,
The mole ratio of the acid, H₃PO₄ (nA) = 1The mole ratio of the base, NH₃ (nB) = 3How to determine the molarity of NH₃ Volume of acid, H₃PO₄ (Va) = 25 cm³Molarity of acid, H₃PO₄ (Ma) = 1.25 mol/dm³Volume of base, NH₃ (Vb) = 45.3 cm³ Molarity of base, NH₃ (Mb) = ?MaVa / MbVb = nA / nB
(1.25 × 25) / (Mb × 45.3) = 1 / 3
31.25 / (Mb × 45.3) = 1 / 3
Cross multiply
Mb × 45.3 = 31.25 × 3
Divide both side by 45.3
Mb = (31.25 × 3) / 45.3
Mb = 2.07 mol/dm³
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Which of these statements are true? Select all that apply. The Delta. Hf for Br2(I) is 0 kJ/mol. The Delta. Hf for He(I) is 0 kJ/mol. The Delta. Hf for Hg(I) is 0 kJ/mol. The Delta. Hf for Cl2(g) is 0 kJ/mol. The Delta. Hf for N2(I) is 0 kJ/mol.
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The enthalpy of formation of liquid mercury and gaseous chlorine are zero because the substance are in their standard state.
The standard state of a substance is the form in which it is found under standard conditions. This include a pressure of 1 atm, a temperature of 298 K and a a concentration of 1 M.
The enthalpy of formation of a substance in its standard state is 0 KJ/mol. The following substances has ΔHf of 0 kJ/mol.
ΔHf of Hg(I) is 0 kJ/mol. ΔHf of Cl2(g) is 0 kJ/molLearn more: https://brainly.com/question/13164491
is it NaCO3 or Na2CO3?
Answers
Copper can be also be made by reacting copper oxide with methane
as shown below.
4CuO + CH4 + 4Cu + 2H2O + CO2
How many moles of copper would be made if:
a) 2 moles of copper oxide were reacted with 2 moles of methane?
b) 2 moles of copper oxide were reacted with 1 mole of methane?
c) 10 moles of copper oxide were reacted with 2 moles of methane?
Answers
Answer:
a
Explanation:
A teacher places a cup of coffee onto an electronic balance at the front of the science laboratory. The teacher then adds three large teaspoons of sugar to the coffee. The volume of the coffee does not appear to increase. What happens to the mass displayed on the front of the balance?
Answers
Answer:
it will be same as before
Answer:
The mass on the balance stays the same
Explanation:
.
Question 1 of 11 The graph shows the change in temperature of a sample of water in a closed system as thermal energy is added over time. 150°C 100°C TELE Temperature (°C) 50°C 0°C -50°C 10 20 30 40 Time (min) 50 60 What happens in the water during changes of state? A. Its particles move at a lower speed B. Its particles maintain a constant speed. c. Its temperature varies constantly D. Its temperature increases slowly
Answers
Answer:
B. Its particles maintain a constant speed
Explanation:
Just did it :D
The graph shows the change in temperature of a sample of water in a closed system as thermal energy is added over time. 150°C 100°C Temperature (°C) 50°C 0°C -50°C 10 20 30 40 Time (min) 50 60 during changes of state water particles maintain a constant speed. Therefore, option B is correct.
What is thermal energy ?The term thermal energy is defined as the energy contained within a system that is responsible for its temperature.It is formed when the atoms and molecules in a substance vibrate faster due to a increase in temperature.
The examples of thermal energy sources are fossil fuels like natural gas, coal and oil, and solar heat, heat pump electric heat, and geothermal heat.
Thus, during changes of state water particles maintain a constant speed, option B is correct.
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The molar mass of water (H2O) is 18. 0 g/mol. A sample of water has a mass of 18. 0 g. How many moles of water are contained in this sample? 1. 00 18. 0 36. 0 324.
Answers
1 mole of water is contained in a sample of water that has a mass of 18.0 g.
HOW TO CALCULATE NUMBER OF MOLES:
The number of moles of a substance can be calculated by dividing the mass of that substance by its molar mass.
no. of moles = mass ÷ molar mass
According to this question, a sample of water has a mass of 18.0g. The number of moles is calculated as follows:
no. of moles of H2O = 18.0g ÷ 18g/mol
no. of moles of H2O = 1mol
Therefore, 1 mole of water is contained in a sample of water that has a mass of 18.0 g.
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explain how redox reactions are involved in energy exchanges
Answers
Redox reactions involve one substance losing electrons (oxidized) and another substance gaining electrons (reduced) in the same reaction. As electrons are transferred between substances, the electrons lose potential energy and energy is released.
Which statement does not identify a characteristic of antibodies?
A They are produced by the body in response to the presence
of foreign substances.
B They may be produced in response to an antigen.
© They are nonspecific, acting against any foreign substance in
the body.
D They may be produced by white blood cells.
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Answer:
they are produced by the body in response to the presence of foreign substance
What is the correct formula
for tin(II) chloride dihydrate?
Answers
the answer is A. SnCl2 . 2H2O
why are earthquakes different in New Madrid than in California.
Answers
Distance traveled over a period of time is?
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Answer:
AVERAGE speed is the total distance traveled divided by the elapsed time.Answer: Average speed is the total distance traveled divided by the elapsed time. (Average speed is not the magnitude of the average velocity.) Speed is a scalar quantity; it has no direction associated with it.
Facts about traveling: Travel is the movement of people between distant geographical locations. Travel can be done by foot, bicycle, automobile, train, boat, bus, airplane, ship or other means, with or without luggage, and can be one way or round trip.
(b) at 400k both compounds are gases. at this temperature, which compound, ch4(g) or ccl4(g), behaves more like an ideal gas? justify your answer, including reasoning about both molecules.
Answers
CH4 has more ideal gas behavior than CCl4 due to its higher intermolecular interaction.
We must note that ideal gases have minimal interaction with each other. Hence, in deciding which gas has ideal gas behavior, we have to consider the gas that has the least degree of intermolecular interaction.
However, the both gases contain nonpolar molecules but CCl4 has a greater molecular mass and has more intermolecular interaction than CH4 hence CH4 has greater ideal gas behavior than CCl4.
Learn more about ideal gas: https://brainly.com/question/8711877
what activity occurs in the process of photosynthesis
Answers
Answer:
Photosynthesis is the process in which light energy is converted into chemical energy in the form of sugars. In a process powered by light energy, glucose (and other sugars) molecules are created from water and carbon dioxide, while oxygen is released as a by-product.Explanation:
i'm mexican
help i cant do this i need this ASAP
Answers
Answer:
you draw the line first to the light bulb and then you connect it to the battery then you connect it to microscope
Explanation:
hope this helped pls mark it brainlest pls and thank you:)
Helpppppppp plzzzzzz asaaaapppp
Answers
Answer:
Alright, the first thing we have to do is to balance the chemical equation
2Na3N -----> 6Na + 1N2
We have 60g of Na3N, we convert them into moles by dividing the mass of the compound by the molar mass.
Molar mass of Na3N = (22.98 x 3) + (14) = 82.94g/mol
60 = 0.72341451651 moles of Na3N
82.94
Now because we did the balanced equation, we know the mole to mole ratio of Na3N to N2 would be 2:1, so in order to get the moles of N2 you have to divide the moles of Na3N by 2
0.72341451651 moles/2 = 0.361707258 moles of N2
Now that we have the moles of N2, we just have to determine the mass of it in grams. In order to do that, just multiply the moles by the molar mass of N2 (28g/mol)
0.361707258 x 28 = 10.13g of N2
Therefore the decomposition of 60g of Na3N would result in 10.13g of N2 (nitrogen gas)
When a magnesium is heated, it burns in air with a dazzling white flame to form a white powder .What it called?
Answers
Balanced Equation –
[tex]\purple{\bf{2Mg + O_2 = 2MgO}}[/tex]
Physical states –
Magnesium → Mg ( In Solid State) Oxygen → [tex]\sf{O_2}[/tex] ( Gaseous State) Magnesium Oxide → MgO ( In Solid State Or White powder)_______________________________________
It is magnesium Oxide MgO2
How many molecules are present in a sample that is 89 g of H2O?
Answers
[tex]\qquad[/tex][tex] \pink{\bf\longrightarrow { Molar \:mass \:of \:H₂O:-} }[/tex]
[tex]\qquad[/tex][tex] \sf \longrightarrow 1\times +16[/tex]
[tex]\qquad[/tex][tex] \sf \longrightarrow 18g[/tex]
[tex]\qquad[/tex]____________________
Let's calculate the number of moles present in 89g of H₂O.
[tex]\qquad[/tex][tex] \purple{\bf\longrightarrow { No \:of \:moles = \dfrac{Given \:mass}{Molar\: mass}}}[/tex]
[tex]\qquad[/tex][tex] \sf \longrightarrow \dfrac{89}{18}[/tex]
[tex]\qquad[/tex][tex] \sf \longrightarrow 4.94\: moles[/tex]
We know –
Avogadro number = 6.022×10²³Number of molecules:-
[tex]\qquad[/tex][tex] \purple{\bf \longrightarrow No \: of \: moles \times Avogadro \: number}[/tex]
[tex]\qquad[/tex][tex] \sf \longrightarrow 4.94×6.022×10²³[/tex]
[tex]\qquad[/tex][tex] \sf \longrightarrow 2.98 ×10²⁴[/tex]
[tex]\qquad[/tex][tex]\purple{ \bf \longrightarrow 2.98×10²⁴ molecules}[/tex]
Thus, 2.98×10²⁴ molecules are there in 89g of H₂O.[tex]\qquad[/tex]____________________
1. SEP Developing and Using Models Look at the data in the table. Construct a
graph of the atomic numbers versus melting point temperature. Plot each group
using a different color or symbol so that you can tell them apart. Remember to
assess the range of the data before deciding on the scale for each axis.
Answers
Answer: do you syill need help on it i am happy to help
Explanation: TELL ME
Rewrite 5.13467 X 10-6 in correct standard form