Answer:
hydrogen and helium is the answer.
look at attachment please help with it, will mark brainliest <3 BUT ONLY IF CORRECT
 A car follows a curved highway from point a to point B covering a distance of 50 km and displacement to the east of 40 km in 0.5 hours. What is the speed and velocity of a car in kilometers per hour? Speed: Km/h. Velocity: Km/h.
Distance = 50 Km
Displacement = 40 Km
Time = 0.5 hours
We know, speed = [tex] \sf \frac{distance}{time} [/tex]
Therefore, the speed of the car
[tex] \sf = \frac{50}{0.5} = 100[/tex]
We know, velocity = [tex] \sf \frac{displacement}{time} [/tex]
Therefore, the velocity of the car
[tex] \sf = \frac{40}{0.5} = 80[/tex]
Answer:
Answer:The speed of the car is 100 Km/h. The velocity of the car is 80 Km/h to the east.
Hope you could get an idea from here.
Doubt clarification - use comment section.
What causes an echo?
refraction
rarefaction
reflection
please help
Write the charges for each part of this equation.
Answer:
the Aluminium Al have +3 charges and idion have I) have - 2 charges
"It is not the union that organizes the employees; it is management."
The statement "it is not the union that organizes the employees; it is management " means that :
The management creates the climate which allows the union to convince employees to accept union representation.This excerpt shows that although the union helps in the organization of employees for better and easy management of staffs by the management, the management creates an enabling environment by creating stipulations which allows the u ions to convince staffs to join and accept union representation in staff welfare matters.
Hence we can conclude that, the management creates the climate which allows the union to convince employees to accept union representation.
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The boiling points of five liquids have been measured 10 times each by a team of scientists, with fairly consistent results. Which next step would be the most logical?
1. Test a sixth liquid to see if it follows patterns in the rest of the data.
2. Use a new thermometer to make sure that the original one was not faulty.
3. Continue collecting data until exact boiling points can be found.
4. Test the results an eleventh time, and average the new trial into the data.
Answer: Test a sixth liquid to see if it follows patterns in the rest of the data.
Explanation:
took the test
Temperature measures the average kinetic energy of particles of the substances. Therefore, the correct option is option A. Temperature is a physical quantity.
What is temperature?Temperature is used to measure degree or intensity of heat of a particular substance. Temperature is measured by an instrument called thermometer.
Temperature can be measured in degree Celsius °c, Kelvin k or in Fahrenheit. Heat always flow from higher temperature source to lower temperature source.
We can convert these units of temperature into one another. The relationship between degree Celsius and Fahrenheit can be expressed as:
°C={5(°F-32)}÷9
The boiling points of five liquids have been measured 10 times each by a team of scientists, with fairly consistent results. the next step would be to Test a sixth liquid to see if it follows patterns in the rest of the data.
Therefore, the correct option is option A.
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which two groups of the periodic table contain the most chemically reactive metals?
Answer:
group 3 and 12 alkali and alkaline earth metal
Explain the reason that maps must change over time
Explanation:
Because the place on the map can be changed to another shape by natural effects like faulting,folding , volcanism
Answer:
Maps must change over time as the geographical structures change from time o time. The roads and highways also change often due to the development activities .
Which of these would describe a dish that contains bits of chocolate and nuts you can see?
homogeneous mixture
compound
heterogeneous mixture
none of the above
Answer:
mezcla homogénea
Answer:
heterogeneous mixture
Explanation:
you can split the mixture easily with you hands while homogeneous mixtures is dissolved
Solve the following problems and show the complete solutions.
1. How many moles of Carbon Dioxide is equivalent to 1.5X1023 atoms of CO2?
2. If you have 5grams of pure Aluminum, (Al), how many atoms does it have? (Al=27)\.
3. If 3 moles Sodium (Na) reacts with exact Chlorine gas (Cl2) in this reaction: 2Na + Cl2 ---> 2NaCl How many mole of Sodium Chloride (NaCl) will be produced?
4. Give the mass percent composition of Potassium, Sulfur and Oxygen in a molecule of Potassium Sulfate: K2SO4.(atomic mass: K=39, S=32).
5. If 162g of Aluminum reacts with 144g of Oxygen gas to form Aluminum oxide, what is the mass percentage of Aluminum?
6. A sample was analyzed and found to contain 40% Carbon. 6.71% Hydrogen and 53.29% Oxygen. If the molecular mass of this compound is 18.16g/mol, what is the empirical and molecular formula of this compound?
The molecular formula of the compound is C6H12O6.
1) We know that;
1 mole of CO2 contains 6.02 X 10^23 atoms
x moles of CO2 contains 1.5 X 10^23 atoms
x = 1 mole X 1.5 X 10^23 atoms /6.02 X 10^23 atoms
x = 0.25 moles of CO2
2) 1 mole of pure Al has 27 g
x moles of Al has 5 g
x = 1 mole × 5 g/ 27 g
x = 0.19 moles
If 1 mole of Al contains 6.02 X 10^23 atoms
0.19 moles of Al contains 0.19 moles × 6.02 X 10^23 atoms /1 mole
= 1.14 X 10^23 atoms
3) From 2Na + Cl2 ---> 2NaCl;
2 moles of Na produces 2 moles of NaCl hence 3 moles of Na will also produce 3 moles of NaCl.
4) The molar mass of K2SO4 is obtained from;
2(39) + 32 + 4(16) = 78 + 32 + 64 = 174 g/mol
Now;
Percentage by mass of K = 2(39)/ 174 × 100/1 = 44.8%
Percentage by mass of S = 32/174 × 100/1 = 18.4%
Percentage by mass of O = 4(16)/174 × 100/1 = 36.8%
5) The reaction equation is;
4Al(s) + 3O2(g) ----> 2Al2O3
Total mass present = 162g + 144g = 306 g
Mass percent of Al = 162g/ 306 g × 100/1 =52.9%
6)
C - 40/12 H - 6.71/1 O - 53.29/16
C - 3.33 H - 6.71 O - 3.33
Dividing through by the lowest ratio
C- 3.33/3.33 H - 6.71/3.33 O - 3.33/3.33
C - 1 H - 2 O - 1
The empirical formula is CH2O
Now;
[12 + 2(1) + 16] n = 180.16
30n = 180.16
n = 180.16/30
n = 6
The molecular formula is C6H12O6.
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Which of the liquids will sink in milk?
Answer:
mercury 13.6 has a great density than milk
which option can be classified as a pure substance
A. solution
B. compound
C. homogeneous mixture
D. heterogeneous mixture
Answer:
B. compound
Explanation:
A pure substance can be an element, which consists of only one type of atom and cannot be broken down by a chemical change, or a compound, which consists of two or more types of atoms.
which of the following describes how ice could have once covered warm places such as australia and india
Answer:
U shaped vallies?
Explanation:
(i dont know if this was one of the options)
what element generally appears in the formula of an acid
Answer:
Hydrogen, hope this helps :)
Alkaline batteries adopted their name from the _____ that is present in the reactions at both the zinc anode and the MnO2 cathode.
Answer:
hydroxide ion
Explanation:
The alkaline battery got this name because it has an alkaline electrolyte of potassium hydroxide.
The energy required to cause a gaseous atom or ion to release a electron is what?
Answer:
The ionization energyExplanation:
The ionization energy is required to cause a gaseous atom or ion to release a electron.
Chemical reactions project modeling the conservation of mass pls help just need answer
The law of conservation of mass states that
In any chemical reaction mass is neither created nor destroyed rather it remains conserved
Mass of reactants=Mass of productsLook the chemical reaction below
[tex]\\ \sf\longmapsto 2H_2+O_2=2H_2O[/tex]
Count the mass on both sides and simplify
It will be 18g and ratio remains onehow to tell if something is a strong or weak acid or base
Answer:
It basically depends upon the pH value of that acid or Base. That's how you can determine whether the substance is a strong or weak acid/base. We have a pH scale ranging from 1 to 14, where 7 is the neutral point. Any substance having a pH of 7 means it is neither an acid nor a Base, but neutral in nature, such as water([tex]H_{2}O[/tex]). Now, if the pH is less than 7, the substance is an acid, similarly if the pH is more than 7, it is a base. As the pH DECREASES, the substance becomes more acidic, on the other hand as the pH INCREASES, the substance becomes more basic. This way you can compare between pH values of two substances and tell which one is stronger or weaker.
For Acids:
If a substance's pH is between 1 and 7 it is an acid. If it is more towards 1, it's a strong acid and if it's more towards 7 it is a weak acid.
For Bases:
If a substance's pH is between 7 and 14 it is a base. If it is more towards 14, it's a strong base and if it's more towards 7 it is a weak base.
Hope that helps...
the two stages that take place during distillation are. a.evaporation is folloeed by condensation. b.condensation followed by evaporation
Answer:
evapiration followed by condensation
A molecular compound is found to consist of30.4% nitrogen and 69.6% oxygen. Ifthe molecule contains 2 atoms of nitrogen, what is the molar mass of the molecule
Answer:
92.01 g/mol
Explanation:
So first you need to find the empirical formula by the percents. That would be, assuming that you have 100 grams of the the sample, divide each quantity of each element found by its respective molar mass.
30.4 g of N ÷ 14 g/mol N= 2.17 mol of N
69.6 g of O ÷ 16g/mol= 4.35 mol of O
You can establish now the empirical formula.
N2.17O4.35,
but since you can't have a decimal subscript, you divide each subscript by the minimum subscript
NO2
So then you're said that the molecular formula derived from that empirical formula has 2 nitrogen, so you multiply all the subscripts, by 2:
N2O4
-Dinitrogen Tetraoxide
-Nitrogen oxide (IV)
Then all you have to do is find the molecular mass of the compound using the periodic table and what you obtain is the molar mass.
remember: molecular mass is correspondent to molar mass.
Given the equation
N2(g) +3H2 (g)--> 2NH3 (g)
1 mole of N2 gas is needed to completely react with 3 moles of H2 gas.
How many molecules of H2 gas are needed?
Answer:
numbers of molecules = 3×6.023×10-23
Of the following elements, which one has the smallest first ionization energy?
A. boron
B. carbon
C. aluminum
D. silicon
Answer:
C. Aluminum
Explanation:
Aluminum has 5.9858 ionization energy
Boron has 8.298 ionization energy
Silicon has 8.1517 ionization energy
Carbon has 11.2603 ionization energy
What is the noble gas notation of Titanium in the ground state?
how many moles of copper are there in 6.93 g of copper sample
pls be quick
[tex]\\ \sf\longmapsto No\:of\;moles=\dfrac{Given\:mass}{Molar\:mass}[/tex]
[tex]\\ \sf\longmapsto No\:of\:moles=\dfrac{6.93}{63.5}[/tex]
[tex]\\ \sf\longmapsto No\:of\:moles=0.109\approx 1.11moles[/tex]
what has fewer organisms then a domain but it also has more organisms then a phylum
Answer:
a species
Explanation:
Please help me, trying to get all my hw done
Answer:
C. size and shape
Explanation:
Physical properties such as size, shape, color, density, magnetism or the
ability to sink or float can be used to separate the substances in a mixture..
Filtration is when matter is passed through a filter and the larger particles
are separated out. Magnets can be used to separate magnetic matter from
non-magnetic matter in a mixture. Objects that float when placed in water
can be separated from those that don’t by placing the mixture in water.
7. What is the mass of 389 cm°of propane if the density is 19.3 g/cm?
We are given that–
Volume of Propane is = 389 cm³Density of Propane is = 19.3 g/cm³[tex]\qquad[/tex]________________________
As we know –
[tex]\qquad[/tex][tex] \pink{\bf\longrightarrow {Mass = Volume \times Density } }[/tex]
[tex]\qquad[/tex][tex] \bf\longrightarrow Mass_{(Propane)} = 389 \times 19.3 [/tex]
[tex]\qquad[/tex][tex] \bf\longrightarrow Mass_{(Propane)} = 7507.7 \: g[/tex]
Hence, Mass of Propane is 7507.7 g.[tex]\qquad[/tex]______________________
Mass of a substance is the amount of the constituting particles per unit volume. The mass of the [tex]\bold { 389\ cm^3}[/tex] of propane is 7.507 kg.
Mass of a substance is the amount of the constituting particles per unit volume. It is measured in kilograms (kg).
The formula for mass,
M = v x d
Where,
M - mass
v - volume = [tex]\bold { 389\ cm^3}[/tex]
d - density = 19.3 g/cm
Put the values in the formula,
M = [tex]\bold { 389\ cm^3}[/tex] x 19.3 g/cm
M = 7507.7 g
M = 7.507 kg
Therefore, the mass of the [tex]\bold { 389\ cm^3}[/tex] of propane is 7.507 kg.
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Carbon-12 contains 6 protons and 6 neutrons and electrons. which subatomic particle, if charged, would change identity of the elements.
A. proton
B. neutron
C. electron
D. all of the elements
Which of the following compounds will have the highest boiling point?
MgCl2
CO2
C12H22O12
,
H2O
Melting gold with other metals makes 10-karat gold. Which term best describes 10-karat gold?
compound
homogeneous mixture
heterogeneous mixture
pure substance
Answer:
I think its a homogeneous mixture (pls correct me if im wrong)
Explanation:
It is a homogeneous mixture because its an alloy made of gold, silver, copper, and other metals that are melted together. A homogeneous mixture is composed of a uniform composition of particles.
There are two types of mixture, one is homogeneous mixture and other is heterogeneous mixture. Therefore, the term best describes 10-karat gold is homogeneous mixture.
What is mixture?When two or more compounds are combined but each ingredient retains its chemical identity, the result is referred to as a mixture. In other words, there is no chemical interaction between the parts of a combination. According to how consistent they are and how well the components' particle sizes match up, mixtures are categorized.
Because it is an alloy comprised of melted gold, silver, copper, and other metals, it is a homogenous combination. A homogeneous mixture has a consistent distribution of its constituent particles.
Therefore, the term best describes 10-karat gold is homogeneous mixture.
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