Answer:
indicates that the substance is in a gaseous state
describe the formation of ionic bonds in potassium chloride compound (5 marks)
Answer:
When the two atoms are in contact, potassium readily transfers its outer electron to chlorine which readily accepts it, resulting in both atoms achieving a state of eight outermost electrons. With this electron transfer, the ionic bond in KCl is formed.
Hydrogen gas (H2) is a promising alternative to fossil fuels. How many molecules are present in 1.0 kg of hydrogen gas
Answer:
3.01×10²⁶ molecules
Explanation:
From the question given above, the following data were obtained:
Mass of H₂ = 1 Kg
Number of molecules =?
From Avogadro's hypothesis,
1 mole of H₂ = 6.02×10²³ molecules
But 1 mole of H₂ = 2 × 1 = 2 g
Now, we shall determine the number of molecules present in 1 Kg (i.e 1000 g) of H₂ as follow:
From Avogadro's hypothesis,
2 g of H₂ = 6.02×10²³ molecules
Therefore,
1000 g of H₂ = 1000 × 6.02×10²³ / 2
1000 g of H₂ = 3.01×10²⁶ molecules
Thus, the number of molecules present in 1 Kg (i.e 1000 g) of H₂ is 3.01×10²⁶ molecules
What is the wavelength of a wave that has a frequency of 6.1 x 109 Hz ? c = λυ where c = 2.998 x 108 m/s
a. 20.4 m
b. 2.04 m
c. 0.49 m
d. 0.049 m
Answer:
Wavelength = 0.049 m
Explanation:
Given that,
The frequency of a wave,[tex]f=6.1\times 10^9\ Hz[/tex]
We need to find the wavelength of the wave. We know that,
[tex]c=f\lambda\\\\\lambda=\dfrac{c}{f}\\\\\lambda=\dfrac{2.998 \times 10^8}{6.1\times 10^9}\\\\\lambda=0.049\ m[/tex]
So, the wavelength of the wave is 0.049 m.
Which statement is the best description of a chemical bond
Answer:
What are your given options? I can't answer unless I know those :)
Explanation:
What is a rechargeable battery?
a group of electrochemical cells that can be recharged
a group of electrolytic cells that can be recharged
a group of electrochemical cells that do not need recharging
O a group of electrolytic cells that do not need recharging
WILL GIVE BRAINLIEST
Answer:
a group of electrochemical cells that can be recharged
Metals like potassium and sodium are kept in paroffin oil. Why?
Answer:
because they are high reactive to the air thats why we keep them in paroffin oil
Because electrons are orbiting the nucleus, the nucleus is stationary
true or false
Answer:
false, The nucleus of atoms still move around like crazy, it's just the electrons move more.
An empirical research method in which data are gathered from observations of phenomena, hypothesis are formulated and tested, and conclusions are drawn that validate or modify the original hypothesis is known as the: Group of answer choices Gotham theory Scientific Method Niels-Bohr hypothesis Entropy theory
Answer:
Scientific Method
Explanation:
Science is empirical in nature. The entire purpose of science is to discover new knowledge.
The empirical research method in science all begins with gathering observations from phenomena. After that, the researcher formulates appropriate hypothesis which are rigorously tested.
The conclusions drawn from testing the original hypothesis validate or modify the original hypothesis.
Why Should a magnesium ribbon be cleaned before burning ?
A magnesium ribbon is cleaned to remove the protective layer of basic magnesium carbonate from its surface, so that it may readily combine with the oxygen in air (on heating).
Answer:
Magnesium gets covered with a layer of magnesium oxide when kept in air for a long time. This layer hinders the burning of magnesium. Hence, it is to be cleaned before burning.
How many moles of water vapor are formed. when 10 litres of butane gas c4h10 is burned in oxygen at STP
Using the idea of the molar volume of butane gas, we have 2.23 moles of water vapor.
What is a reaction equation?The term reaction equation shows the conversion of reactants to products. First of all, we must get down the reaction equation as follows;
C4H10(g) + 13/2O2(g) ----> 4CO2 (g) + 5H2O(g)
From the balanced reaction equation;
1 mole of butane gas yields 5 moles of water vapor. Since 1 mole of butane gas occupies 22.4 L. Hence;
22.4 L of butane yields 5 moles of water vapor
10 L of butane gas yields 10 L * 5 moles/22.4 L = 2.23 moles
Learn more about butane gas:https://brainly.com/question/6665698
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
Answer:
uh i think this is the answer
Explanation:
Select the correct answer.
0.22 M
HCI
Unknown
LiOH
What is the concentration of the base (LIOH) in this titration?
1.0 ml
0.5 ml
Initial
burette
reading
Final
burette
reading
13.3 ml
18.5 ml
OA
0.16 M
ОВ.
0.15 M
OC. 0.22 M
OD
18 M
O E
0.5 M
Daset
Answer:
=0.15M
Explanation:
To get the moles of the unknown LiOH, calculate the number of moles of HCl in 12.3mL.
Using the stoichiometric coefficient, mole ratio 1:1.
This means that the number of moles is the same. This number of moles is contained in 18mL. Then Calculate the molarity (concentration) which is in 1000mL
See the explanation from the image I have shared with you for calculations.
(Please help)
1.what is the most common isotope for element x
2.calculate the average atomic mass for element x
Answer:
1. Isotope with mass number 39.
2. 39.02g/mol
Explanation:
1. The most common isotope is the isotope in the higher proportion, that is:
Isotope with mass number 39.
2. The average atomic mass is the sum of the masses times their abundance. For the element X:
Average atomic mass:
38*0.0967 + 39*0.7868 + 40*0.1134 + 41*0.0031
= 39.02g/mol
An atom has9 electrons and 9 protons at the start. If it loses 2 electrons, what would the net charge on the atom be
Answer:
i hope it will help you
Explanation:
there will be 7 electrons and 9 protons will have 2+ charge.
explain with example the need of standard measurement system
Answer:
A standard system of measurement is very important because it helps us from making mistakes at the moment of doing calculations and correctly working...
Answer:
A standard measurement system is important because it allows scientists to compare data and communicate with each other about their results. Metric System – is a measurement system based on the number 10.
1 x 10^-3 m is the same as which of the following? Select all that apply.
a
10000 m
b
1/1000 m
c
1/0.1 m
d
0.001 m
e
100 m
Answer: b and d
Explanation:
1×10^-3=1×1/10³=1×1/1000=1/1000 so b is correct
1×10^-3=1/1000=0.001
so d is correct
Balancing equations
1. __Na + __Oz -> __Na2O
Answer:
Balancing equations
1
[tex]4Na + O_{2} -> 2Na_{2}O[/tex]
If an equilibrium system contains gaseous reactants and/or products, a change in volume will cause a change in concentration and pressure. A decrease in volume will cause the system to shift in the direction that produces _____ moles of gas in total, whereas an increase in volume causes a shift in the direction that produces _____ moles of gas in total.
Answer:
Less
More
Explanation:
When a constraint is imposed on a reaction system in equilibrium, the equilibrium position will shift in such a way as to annul the constraint.
When the volume of a reaction system in equilibrium is decreased, the equilibrium position will shift in the direction having less total number of moles.
Similarly, when the volume is increased, the equilibrium position shifts to the direction having a greater total number of moles.
Question 3 of 10 What does the first ionization energy represent? O A. The energy required to add an electron to a new energy level B. The energy to remove an energy level of electrons O C. The energy given off when an electron is gained D. The energy required to remove an electron from an atom SUBMIT
Answer:
D
Explanation:
The first ionization energy is the minimum energy required to remove the most loosely bound electron from an atom.
Good luck!
What is the general function of enzymes in the human body?
O A. They make fatty acids unsaturated.
OB. They speed up chemical reactions.
O C. They store genetic information.
D. They carry instructions for making proteins.
Answer:
C
they store genetic information
B. They speed up chemical reactions
which states of matter can flow from one place to another
Answer:
Liquid
Explanation:
Quite an easy question!
Answer:
Liquid
Explanation:
I was passing by lol
A toy plane has a mass of 2.5kg and is 18 m above the ground. It is moving 4.5 m/s.
how much mechanical energy does the toy have?
A. 416J
B. 441J
C. 466J
D. 491J
Answer:
466J (c)
Explanation:
Mechanical Energy= Kinetic+Potential
Potential energy= mgh
Plug in givens
mgh=2.5*18*9.8=441J
Kinetic Energy = 1/2mv^2
Plug in givens
1/2mv^2= 1/2(2.5)(4.5)^2= 25.3125J
Mechanical energy= 441J+25.3125J=466.3125J or 466J
7. (a) Using two examples, explain how covalent compounds are formed. [4 marks]
(b) State three physical properties of covalent compounds. [3 marks]
(c) Describe an experiment how you can carry out an experiment to investigate one of the properties mentioned above. [3 marks]
8. (a) Using two examples, explain how covalent compounds are formed. [14 marks]
(b) State three physical properties of covalent compounds.[3 marks]
Describe an experiment how you can carry out an experiment to investigate one of the properties mentioned above. [3 marks]
Answer; a) Covalent compound are formed when atoms of different molecules share electrons in order to be stable either by losing or gaining electrons
eg.. HCL hydrogen chloride , a chlorine atom has 7 electrons on its outer shell and hydrogen has 1 so when this two pair they become covalently bonded. chlorine shares one electron with the hydrogen atom ,thus to say both now have a stable arrangement of electron in their outer shell.
methane CH4 the carbon atom has 4 electrons and hydrogen has 1 so carbon would need 4 more and hydrogen would need 1 more so carbon pairs with 4 hydrogen atoms making it 8 and hydrogen 2 so they now have a stable arrangement ,thus the carbon atom shares with 4 hydrogen atoms.
b) some physical properties are
i)they have low melting and boiling points
ii)their insolubility in water
iii) they are non conductors of electricity
c) an experiment using their melting and boiling point
EXPERIMENT; lets use the covalent molecule carbon monoxide CO
when you apply heat and it tend to melt at a -199 degree celsius then it is a covalent molecule
and when it starts to boil at -191 degree celsuis then its sure a carbon monoxide covalent molecule
explanation; the reason for its low melting point and boiling point is because the attraction between the molecule is very low so it doesn't need much energy to break up the lattice between them.
HOPE THIS HELP if you need more explanation feel free to comment in the comment section
How are carbon-based molecules suited for sustaining life?
[tex]\huge\fcolorbox{red}{pink}{Answer ♥}[/tex]
Life on Earth is based on carbon, likely because each carbon atom can form bonds with up to four other atoms simultaneously. This quality makes carbon well-suited to form the long chains of molecules that serve as the basis for life as we know it, such as proteins and DNA.
Hope it helps uh ✌️✌️✌️
A balloon, inflated in an air-conditioned room at 27.0°C, has a volume
of 4.50.L. It is heated to a temperature of 57.0°C. What is the new
volume of the balloon if the pressure remains constant?
Answer:
4.95L
Explanation:
Using Charle's law equation;
V1/T1 = V2/T2
Where;
V1 = initial volume (L)
V2 = final volume (L)
T1 = initial temperature (K)
T2 = final temperature (K)
According to the question, the following information was given:
V1 = 4.50L
V2 = ?
T1 = 27°C = 27 + 273 = 300K
T2 = 57°C = 57 + 273 = 330K
Using V1/T1 = V2/T2
4.50/300 = V2/330
Cross multiply
300 × V2 = 4.5 × 330
300V2 = 1485
V2 = 1485 ÷ 300
V2 = 4.95L
why is the reaction of Iron and hydrochloric acid slow
Answer:
The chloride formed when iron reacts with hydrochloric acid is iron (II) chloride, also known as iron dichloride. The reaction between iron and hydrochloric acid is slower than the reaction with zinc, with much smaller hydrogen bubbles produced.
Answer:
The reaction of iron and hydrochloric acid is slow beacause When dilute Hydrochloric acid is added to iron filings, iron(II) chloride & hydrogen gas is produced. In this reaction iron displaces hydrogen from hydrochloric acid to form iron chloride & hydrogen gas this reaction is a single displacement reaction which reacts slowly.
Explanation:
define all the physical features of earth
MOUNTAINS
Mountains are large, tall, and elevated land areas on the earth's surface. They have steep, sloping sides and sharp or rounded ridges, and a high point, called a peak.
PLAINS
Plains are one of the major landforms on earth. They are areas of flat lands.
PLATEAUS
A plateau is a flat, elevated landform that rises above the surrounding area.
DESERTS
Regions of dry, arid lands.
DELTAS
A river delta is a landform created by deposition of sediment that is carried by a river as the flow leaves its mouth and enters slower-moving or stagnant water.
Which is TRUE about the structure of the atom? Select all that apply.
a
the densest part of the atom is the nucleus of the atom
b
the outermost part of the atom is where electrons are found
c
the nucleus of the atom is where protons and neutrons are found.
d
the outer part of the atom is called the antinucleus.
e
the nucleus of the atom has a diameter of about 10-10 m.
he ______ is the depth in the ocean at which calcareous skeletal material first begins to dissolve. Multiple choice question.
Answer: lysocline
Explanation:
Lysocline is the depth in the ocean at which calcareous skeletal material first begins to dissolve. It is the depth of the ocean whereby the dissolution rate of calcite has a dramatic rise.
Lysocline is also referred to as the transition zone upper bound where the CaCO3 content drops.
This is the chemical formula for calcium phosphate:
Ca3PO42.
Calculate the mass percent of oxygen in calcium phosphate. Round your answer to the nearest percentage
Answer:
This is the chemical formula for calcium phosphate:
[tex]Ca_3(PO_4)_2[/tex].
Calculate the mass percent of oxygen in calcium phosphate. Round your answer to the nearest percentage
Explanation:
The molar mass of calcium phosphate is: 310.18g/mol.
In one mole of calcium phosphate there are 8 moles of oxygen atoms.
The atomic mass of oxygen in calcium phosphate is: 128.0 g
Hence, the mass % of oxygen in the given compound is:
[tex]mass% of Oxygen =\frac{mass of oxygen}{mass of calcium phosphate}*100\\&=\frac{128.0g}{310.18g} *100\\&=41.3[/tex]
Hence,mass%of oxygen is 41.3.
