Answer:
law of multiple proportions
Explanation:
The law of multiple proportions states that, if two elements A and B, combine to form more than one chemical compound. Then the various masses of one element A, which combine separately with a fixed mass of element B are in simple multiple ratio.
We can see that the ratio of oxygen that combines with carbon in the two compounds( A and B) is 1:2. This demonstrates the law of multiple proportions.
The substances A and B must be CO and CO2 respectively.
Help ASAP please
Which statement best describes the reaction pathway graph for an exothermic reaction but not an endothermic reaction?
It has a hill in the middle that is the highest point.
It has a valley in the middle that is its lowest point.
The reactants are higher in energy than the products.
The products are higher in energy than the reactants.
Answer: C ) The reactants are higher in energy than the products
Explanation:
The enthalpy that is a state variable that identifies the content of heat. Then the change of enthalpy for the exothermic reactions is negative, meaning that the energy of the products is lower than the energy of the reactants.
what kind of crystalline solid is graphite?
Answer:
Covalent-network (also called atomic) solids—Made up of atoms connected by covalent bonds; the intermolecular forces are covalent bonds as well. Characterized as being very hard with very high melting points and being poor conductors. Examples of this type of solid are diamond and graphite, and the fullerenes.
I hope it's helpful!
Answer:
network solid
Explanation:
The picture has my question
Answer:
b or c
Explanation:
If an oxygen molecule is moving at 4.78 x 104
cm.s-, what is its speed in mi hrl?
Show work please
Answer: 1075.5 mph
Explanation:anything moving at 4.78*10^4 cm/sec
equivalent to
cm —> miles = 1/1.6*10^5
sec —> hr = 1/3600
[4.78*10^4]*3600/1.6*10^5 = 1075.5 mph
which changes when gases condense to form liquids
In condensation, matter changes from a gas to a liquid. All matter is made of tiny moving particles called molecules. Evaporation and condensation happen when these molecules gain or lose energy. This energy exists in the form of heat.
Help solve please, it’s due in less than an hour or so.
sorry i can only figure out 1 but the answer is
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124
hope you do good on your test :D
please help. it’s my last question.
Given
Atomic symbol
Required
Atomic composition
Solution
Atomic number = number of protons = number of electrons
Mass Number (A) is the sum of protons and neutrons
Number of protons and Number of Neutrons in nucleus
Number of electrons in the shell
From the picture:
protons = 3
neutrons = 4
electrons = 3
atomic number = protons = electrons = 3
mass number = protons + neutrons = 3+4 = 7
ANSWER ASAP
2. The figure shows the first three rows, or periods, of the periodic table. Suppose the fourth period is added. How many orbits will the Bohr models in the fourth period have? How many electrons will an atom in Group 1 in the fourth period have?
Answer:
4 orbits in the fourth period.
19 electrons in the atom from group 1 and fourth period.
Explanation:
Potassium has 19 electrons distributed in its 4 orbits
The number of periods in a periodic table, tells the number of shells or orbitals of the atoms in that row in which the electrons are filled. Thus the fourth period elements have 4 orbitals and the first element in group one of the fourth period is potassium containing 19 electrons.
What are periods in periodic table?All elements in a periodic table are classified into different groups and periods. The vertical columns in the periodic table is called groups and the horizontal rows are called periods.
A group contains elements with same number of valence electrons and similar physical and chemical properties. In a period from left to right the atomic number increases but the number of orbitals in which the electrons are filled will be the same.
Down a group the number of orbitals increases by one. Thus, each elements contains electrons in an increment of 8, 18, 18 and 32 down a group. Thus, from third period to fourth period the number of orbital increases to 4.
The number of electrons will be +8 from the previous element in the group in third period. Thus, below sodium (11) the first element in fourth period is potassium with 19 electrons.
To find more on periodic table, refer here:
https://brainly.com/question/11155928
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Which of these describes the essential conclusion of the Rutherford experiment? The atom contains a very small nucleus that contains most of its mass. The proton is positively charged and the neutron has no charge? Atoms are solid spheres with electrons suspended in them like chocolate chips in a cookie. Mass is neither made nor consumed in a chemical reaction.
Answer:
The atom contains a vey small small nucleus that contains most of its mass.
Explanation:
The Rutherford gold leaf experiment concluded that most (99%) of all the mass of an atom is in the nucleus of the atom, that the nucleus is very small (105 times small than the size of the atom) and that is is positively charged.
3. A gram food sample is burned completely in a calorimeter that contains 1000. of water The temperature of the water increases 23.65 degrees * C . How many Calories does the food have per gram ?
The food has 23629.64 cal
Further explanationGiven
mass = 1000 g of water
temperature increases 23.65 * C
Required
The energy of the food
Solution
Heat absorbed by water :
Q = m . c . Δt
Q = 1000 g x 4.184 J/g°C x 23.65 °C
Q = 98951.6 J
1 Joules = 0.2388 Calories
98951.6 J = 23629.64 cal
a reaction vessel contains a small piece of magnesium metal and air (20%) of which is oxygen gas. The mixture is ignited and burns with a burst of light and heat, producing solid magneisum oxide. The mass of mgO, however, is less than the initital mass of magnesium and oxygen combined. What loss of mass
Answer: see below
Explanation:
Mg burning in air gives MgO and a smaller amount of Mg3N2
2Mg+O2=2MgO. 2*24.3+32=2*40.3
3Mg+N2=Mg3N2
Ignoring the nitride, MgO loss of mass during the reaction can be ascribed to
(1) relativistic loss as energy (too small to be measurable)
(2) During the reaction, which is strongly exothermic, a fraction f the material is blown off as tiny particles which adhere to the vessel.
Use the periodic table to select the element that best fits each of the following descriptions.
Noble gas:
O oxygen
O chlorine
Okrypton
Answer:
Krypton
Explanation:
Which of the following is an example of a physical change, but not a chemical change?
Answer:
Boiling Water
Explanation:
Boiling water is an example of physical change and not and not a chemical change because the water vapor still has the same molecular structure as liquid water.If the bubbles were caused by the decomposition of a molecule into gas then boiling would be a chemical change.
Answer:
A chemical change results from a chemical reaction, while a physical change is when matter changes forms but not chemical identity. Examples of chemical changes are burning, cooking, rusting, and rotting. Examples of physical changes are boiling, melting, freezing, and shredding
Explanation:
You are working to earn enough money for a vacation which costs 2100. Your take-home pay is $16.50/hour, but you only work 4-hour shifts each day. How many days will it take for you to earn enough money to pay for your vacation if all the money you earn goes towards your vacation?
Answer:
32 days.
Explanation:
First we determine how much is made in a day.
16.50 x 4 = 66.
Next, we divide 2100 by 66 to reach our amount of days needed.
2100 / 66 = 31.818181... [81 is what repeats over and over.]
We round this up to the nearest whole number. You can't underpay, so you have to round.
The next whole number would be 32, so our answer is 32 days.
Density of water calculation using a 10 mL graduated cylinder
10 mL graduated cylinder + 10 mL unknown liquid (g) 10 mL graduated cylinder (g) Volume of liquid (mL) Density (g/mL)
Trial 1 19.731 9.861 10.0
Trial 2 19.831 9.861 10.0
Trial 3 19.831 9.861 10.0
Trial 4 19.771 9.861 10.0
Trial 5 19.751 9.861 10.0
Required:
Calculate the average density for the gradudated cylinder measurements.
Answer:
Average density of the liquid = 0.992 g/mL
Explanation:
Density = mass/volume
mass of liquid = (mass of liquid + mass of cylinder) - mass of cylinder
Trial 1: mass of liquid = 19.731 - 9.861 = 9.87
volume of liquid = 10 mL
density of liquid = 9.87 g / 10 mL = 0.987 g/mL
Trial 2: mass of liquid = 19.831 - 9.861 = 9.97
volume of liquid = 10 mL
density of liquid = 9.97 g / 10 mL = 0.997 g/mL
Trial 3: mass of liquid = 19.831 - 9.861 = 9.97
volume of liquid = 10 mL
density of liquid = 9.97 g / 10 mL = 0.997 g/mL
Trial 4: mass of liquid = 19.771 - 9.861 = 9.91
volume of liquid = 10 mL
density of liquid = 9.91 g / 10 mL = 0.991 g/mL
Trial 5: mass of liquid = 19.751 - 9.861 = 9.89
volume of liquid = 10 mL
density of liquid = 9.89 g / 10 mL = 0.989 g/mL
Average density = (0.987 + 0.997 + 0.997 + 0.991 + 0.989)/5 = 4.961/5
Average density of the liquid = 0.992 g/mL
What contains more hydrogen atoms, 1.0 mole of H20 or 1.0 moles of НЗО?
H20
H30
both are equal
cannot be determined
(please show ur work)
Pls answer this two ASAP PLSSSSSSSS
Answer:
1. aa
2. They have similar DNA
Explanation:
1. According to the question 1, wrinkled seeds (A) are dominant over round seeds (a) in pea plants. This means that, based on the law of dominance proposed by Mendel, wrinkled seeds will be expressed over round seeds in a heterozygous state (Aa).
However, since the round seed phenotype is a recessive trait, it will only be expressed when the alleles for round seeds (a) are the same in the gene i.e. aa genotype.
2. Based on the information in question 2, Ricky, who is working on a family tree for his school project, realizes that his close relatives all look similar in the pictures he collected. This is possible because of the SIMILARITY OF THEIR DNA (genetic material). Note that, relatives are connected by the genes that are inherited from one another, hence, they possess a similar DNA, which is the most valid reason for the resemblance.
According to the following reaction, how many moles of calcium chloride will be formed upon the complete reaction of 27.9 grams of calcium hydroxide with excess hydrochloric acid? calcium hydroxide (aq) + hydrochloric acid (aq) calcium chloride (aq) + water (l) moles calcium chloride
Answer: 0.377 moles of calcium chloride will be formed.
Explanation:
To calculate the moles :
[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]
[tex]\text{Moles of} Ca(OH)_2=\frac{27.9g}{74g/mol}=0.377moles[/tex]
The balanced chemical reaction is:
[tex]Ca(OH)_2+2HCl\rightarrow CaCl_2+2H_2O[/tex]
According to stoichiometry :
As 1 mole of [tex]Ca(OH)_2[/tex] give = 1 mole of [tex]CaCl_2[/tex]
Thus 0.377 moles of [tex]Ca(OH)_2[/tex] give =[tex]\frac{1}{1}\times 0.377=0.377moles[/tex] of [tex]CaCl_2[/tex]
Thus 0.377 moles of calcium chloride will be formed upon the complete reaction of 27.9 grams of calcium hydroxide with excess hydrochloric acid
20 g of Allg is dissolved in water to produce a solution with a concentration of 2.007M. What is the volume of this solution in milliliters?
Answer:
369 ml
Explanation:
Mass of Aluminium (Al) = 20 g
Molar concentration = 2.007M
Molar concentration = Number of moles / Volume
The relationship between mass and number of moles;
Number of moles = Mass / Molar mass
Number of moles = 20 / 27 = 0.741 mol
2.007 = 0.741 / Volume
Volume = 0.741 / 2.007 = 0.369 L
converting to millilitres by multiplying by 1000
Volume = 0.369 * 1000 = 369 ml
Determine the density (in g/mL) of a substance with a mass of 105 g and a volume of 17.6 mL.
Answer:
Density, d = 5.96 g/mL
Explanation:
Given that,
Mass, m = 105 g
Volume, V = 17.6 mL
We need to find the density of the substance. So,
[tex]d=\dfrac{m}{V}\\\\d=\dfrac{105\ g}{17.6\ mL}\\\\d=5.96\ g/mL[/tex]
So, the density of the substance is 5.96 g/mL.
What important function do currents and areas of upwelling provide for living things
in the sea?
Recycles the ocean water through evaporation and precipitation
Brings nutrients up from deeper water for use by organisms
Mixes land and sea organisms to broaden the food web
Allows Earth to have weather and climate changes
6. Describe nuclear fusion reactions as they
occur in the sun.
Answer:
i wish i know
Explanation:
i wish i know
Which orbital is partially filled in the Zirconium (ZI) atom?
Answer:
4d orbital.
Explanation:
Hello!
In this case, since zirconium's atomic number is 40, we fill in the electron configuration up to 40 as shown below:
[tex]1s^2,2s^2,2p^6, 3s^2,3p^6,4s^2,3d^{10},4p^6,5s^2,4d^2[/tex]
Thus, the orbital 4d is partially filled.
Best regards!
Convert 3.93 x 10-22 grams of X4Z3 into molecules/formula units of the same compound. (Assume that the molar mass of X is 59.45 grams per mole and the molar mass of Z is 13.84 grams per mole.)
Assume that Avogadro's number is 6.022 x 1023. Report your answer to three decimal places.
Answer:
0.847 molecule.
Explanation:
From the question given above, the following data were obtained:
Mass of X₄Z₃ = 3.93×10¯²² g
Number of molecules of X₄Z₃ =?
Avogadro's number = 6.022×10²³ molecules
Next, we shall determine the molar mass of X₄Z₃. This can be obtained as follow:
Molar mass of X₄Z₃ = (4×59.45) + (3×13.84)
= 237.8 + 41.52
= 279.32 g/mol
Finally, we shall determine the number of molecules in 3.93×10¯²² g of X₄Z₃. This can be obtained as follow:
From Avogadro's hypothesis,
1 mole of X₄Z₃ = 6.022×10²³ molecules
But 1 mole of X₄Z₃ = 279.32 g
Thus we can say that:
279.32 g = 6.022×10²³ molecules
Therefore,
3.93×10¯²² g = 3.93×10¯²² × 6.022×10²³ / 279.32
3.93×10¯²² g = 0.847 molecule.
Thus, 3.93×10¯²² g of X₄Z₃ contains 0.847 molecule.
Question 12 (1 point)
You notice light pollution in
a.space
b.big cities
c.rural areas
d.our galaxy
Answer:
the answer is D . our galaxy
Answer:
our galaxy of course
2. What is the final temperature when a 32.0 g piece of diamond at 33.5°C is heated with 360 J of energy?
(Cp = 0.509
Answer:
55.6 °C
Explanation:
From the question given above, the following data were obtained:
Mass (M) of diamond = 32.0 g
Initial temperature (T₁) = 33.5°C
Heat (Q) required = 360 J
Specific heat capacity (C) of diamond = 0.509 J/gºC
Final temperature (T₂) =?
Next, we shall determine the change in temperature. This can be obtained as follow:
The final temperature can be obtained as follow:
Mass (M) of diamond = 32.0 g
Heat (Q) required = 360 J
Specific heat capacity (C) of diamond = 0.509 J/gºC
Change in temperature (ΔT ) =?
Q = MCΔT
360 = 32 × 0.509 × ΔT
360 = 16.288 × ΔT
Divide both side by 16.288
ΔT = 360 / 16.288
ΔT = 22.1 °C
Finally, we shall determine the final temperature. This can be obtained as follow:
Initial temperature (T₁) = 33.5°C
Change in temperature (ΔT ) = 22.1 °C
Final temperature (T₂) =?
ΔT = T₂ – T₁
22.1 = T₂ – 33.5
Collect like terms
22.1 + 33.5 = T₂
T₂ = 55.6 °C
Therefore, the final temperature is 55.6 °C.
How many moles are in 3.01 x 10^23 atoms of zinc?
Answer:
What is ^ for?
Explanation:
35.2 J of heat is
applied to 16.0 g
of a substance.
Temp rises by 7.2
K. Specific Heat?
The specific heat : c = 0.306 J/g K
Further explanationGiven
Heat = 35.2 J
Mass = 16 g
Temperature difference : 7.2 K =
Required
The specific heat
Solution
Heat can be calculated using the formula:
Q = mc∆T
Q = heat, J
m = mass, g
c = specific heat, joules / g ° C
∆T = temperature difference, ° C / K
Input the value :
c = Q / m.∆T
c = 35.2 / 16 x 7.2
c = 0.306 J/g K
How to get the density of this unknown liquid?
Answer:
Measure the volume of water poured into a graduated cylinder, then place the object in the water and remeasure the volume. The difference between the two volume measurements is the volume of the object. Now simply divide the mass by the volume to calculate the density of the object.
14.86 ml + 15.0 ml + 14.980 ml =
Answer:
44.84 ml
Explanation:
14.86
+
15.0
+
14.980
_______
44.84