Answer:
80 m/s.
Explanation:
NOTE: This is a physics question. However, the solution to the question given below:
From the question given above, the following data were obtained:
Acceleration (a) = 2 m/s²
Initial velocity (u) = 20 m/s
Time (t) = 30 s
Final velocity (v) =?
The final velocity of the train can be obtained as shown below:
v = u + at
v = 20 + (2 × 30)
v = 20 + 60
v = 80 m/s
Therefore, the final velocity of train is 80 m/s.
please help. need this asap!!
Answer:
E.....Na2I.,.
Explanation:
Cuz sodium has a Vallency..1......lodide has Vallency 2
Heat is most closely related to which kind of energy?
O nuclear
electrical
thermal
chemical
Answer:
C thermal
Explanation:
Name the following structure:
HOCH2CH2CH2OH
Answer:
I'm pretty sure this is propanediol
Explanation:
I'm not sure how to explain it, but I believe this is the structure for propanediol. Please let me know if I misunderstood and don't hesitate to reach out with questions!
1,3-propan-diol is the chemical name the given structure: [tex]HOCH_2CH_2CH_2OH[/tex].
Chemical names are orderly systems for classifying and identifying various chemical compounds. They act as a benchmark for international scientific and research communication. For the development of many scientific domains, a standardised nomenclature system for chemicals must be created and adopted. Chemical names, which are made up of a combination of words and symbols, include detailed information on the make-up and structure of a certain substance. They frequently contain constituents, functional groups, and distinct modifiers that aid in describing the compound's varied attributes. 1,3-propan-diol is the chemical name the given structure: [tex]HOCH_2CH_2CH_2OH[/tex].
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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.
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 ✌️✌️✌️
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.
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.
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
different oil refineries in UAE
Answer:
Petroleum refinery capacity in the UAE 2009-2018
In 2018, the total production capacities of all refineries in the UAE were 1.13 metric barrels per day. Total total production capacity of the al-Ruwais refinery in the United Arab Emirates was approximately 817,000 metric barrels per day.
3. If there were multiple products comment on finding the mixture melting point of the products. Does your sample appear to be a mixture or pure
Answer:
If there were multiple products, we can take each product and mixed with a sample of a pure compound that we suspect might be the same as the product. Then, we taking the melting point of this mixture that contains one of our product and pure sample. Then, we can observe the change in melting point, if there is no change in melting point or the melting stays in the same range of the pure compound. Then, the that product along with the pure sample are actually the same compound, not a mixture of two compounds. However, if the melting point for our pure sample compound changed or didn't stay in the same range after the mixing with on of our products. then we can conclude that this product and the pure sample are completely different compound, and indeed they are a mixture.
can someone help me?
Answer:
1: because phosphate contain oxide ions so that is base character
Crystals of sodium chloride were prepared by the following method.
1 25.0 cm3
of dilute hydrochloric acid was accurately measured into a conical flask.
2 Aqueous sodium hydroxide was added until the solution was neutral. The volume of
sodium hydroxide added was measured.
3 The solution was evaporated and the crystals washed with approximately 15 cm3
of water.
Which row shows the pieces of apparatus used to measure the 25.0 cm3
of hydrochloric acid, the
volume of aqueous sodium hydroxide and the 15 cm3
of water?
Answer: the answer is C
IF U MIGHT NEED AN EXPLANATION FEEL FREE TO COMMENT
The laboratory equipment like the burette, pipette, and measuring cylinders are used in process of titration process. The solution of NaOH is added by the burette. Thus, option C is correct.
What is titration?Titration has been the analytical technique that uses the known and measured quantity of the solution to estimate the volume of another solution with an unknown volume and known molar concentration.
The laboratory equipment like burette, pipette, and measuring cylinders are used in measuring the volume in the titration process. The burette is filled with sodium hydroxide to measure its quantity.
The pipette is used to transfer the volume of the solution that is known (hydrochloric acid) and the measuring cylinder is used to measure the liquid (water) that is used in chemistry experiments.
Therefore, option C. pipette, burette, and measuring cylinder are the apparatus used in the titration process.
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Lead is a toxic metal that affects the central nervous system. A Pb-contaminated water sample contains 0.0012 % Pb by mass. What volume of the water in milliliters contains 100 mg of Pb
Answer:
8.3 × 10³ mL
Explanation:
Step 1: Calculate the mass of water that contains 100 mg of Pb
The concentration of Pb in the sample is 0.0012% by mass, that is, there are 0.0012 g of Pb every 100 g of water. The mass of water that contains 100 mg (0.100 g) of Pb is:
0.100 g Pb × 100 g Water/0.0012 g Pb = 8.3 × 10³ g Water
Step 2: Calculate the volume corresponding to 8.3 × 10³ g of water
Since the solution is diluted, we will assume the density of the sample is equal than the density of water (1 g/mL).
8.3 × 10³ g × 1 mL/1 g = 8.3 × 10³ mL
The volume of the water in milliliters contains 100 mg of Pb is;
V = 8.3 × 10³ mL
Volume of SolutionWe are given the concentration of Pb in the sample as 0.0012% by mass.
That means that there are 0.0012 g of Pb in every 100 g of water.
Thus, the mass of water that contains 100 mg (0.100 g) of Pb is calculated as;
(0.100 g Pb × 100 g of Water)/0.0012 g of Pb = 8.3 × 10³ g of Water
Now, we know that the density of water (1 g/mL) but we are not given the density of the sample.
Thus, since the solution is diluted we can equally say that;
Density of sample = 1 g/mL
Formula for Volume is;
V = mass/density
Thus;
V = 8.3 × 10³ g/1 g/mL
V = 8.3 × 10³ mL
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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:
(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
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
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
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.
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.
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 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
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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.
Someone please do a True or false of all of these
Answer:
1. False
2. True
3. False
4. False
5. True
6. False
7. True
8. True
9. True
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
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
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.
The most common carrier of communicable diseases are
a.cockroach
b.housefly
c.mosquito
d.spider
housefly
Explanation:
Because it one of the affective vector of disease carrier and it always roam towards wastes and dirty materials likely to get attracted . And it carries contagious disease from hospitals , infected patients , etc .
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
Help ASAP only right answers only no spam don’t answer if you don’t know
Answer:
theory
Explanation:
if you assume something that you didn't see occuring it is called a theory
Kelvin And Mimi studied the fruits. Kelvin concluded that there are more ovules in a mango flower than a papaya flower while Mimi
argued that there are more ovules in a papaya flower than a mango flower.
(a) who is correct?
(b)Explain your answer in (a).
Answer:
kevin is right according to what i see
Anthracite coal d) is the most abundant grade of coal e) is very soft and burns at high temperatures a) causes the most air pollution c) is very hard and burns cleanly b) has the highest sulfur content
Answer: The correct option is C ( is very hard and burns cleanly).
Explanation:
COAL is a form of rock that is made up of mostly carbon amongst other elements which includes sulphur, nitrogen, hydrogen and oxygen. There are different types of coal which include:
--> anthracite ( 90% carbon)
--> bituminous coal ( 70-90% carbon)
--> lignite ( 60- 70% carbon) and
--> peat (60 % carbon).
Anthracite is the type of coal that contains the highest carbon content ( 90% carbon). This makes it very hard and is often a times referred to as HARD COAL. Anthracite is a higher quality coal for domestic and open fire heating. This is because it contains less impurities than other type of coal and thereby making it to BURN CLEANLY avoiding atmospheric pollution.
