Answer:
protons and neutrons
Explanation:
The nucleus of the atom contains protons and neutrons. The electrons of the atom orbit the nucleus.
5. What mass of the following solutes will dissolve in 100 ml of water?
KNO3 at 50o C? ______________________________
NH4Cl at 50o C? _________________________________
NaNO3 at 50o C? _______________________________
Answer: 130g , 40g , 70g
Explanation:
What volume of hydrogen is necessary to react with 6.25g of nitrogen to produce ammonia?
(Assume constant temperature and pressure.)
A. 30L
B. 15L
C. 6.2L
D. 12.5L
Frankie earns $5 each time he babysits his little sister. He has saved $30. Frankie wants to save $52 to buy a new skateboard. How many more times will Frankie need to babysit to have enough money to buy the skateboard?
Answer:
52- the 30 he has already = $22
22/5= 4.4
he will have to babysit 5 times
A cube, with a mass of 21 g is dropped in a graduated cylinder with 10 mL
water. The water level rises to 24 mL when the cube is added. What is the
cube's density (don't forget units)
Answer:55ml
Explanation:
What is electroluminescence? Give one example.
Answer:
electroluminescence is a production of light by the flow of electrons, as within certain crystals. An example is at most resataurants with a bright sign that either says open or closed.
Explanation:
How many moles are in 212.46 grams of H2SO4?
Answer:
2.16622443577839
Explanation:
Answer:
It would be 2.16622443577839.
Explanation:
Which of the following is the most important reason for people to carefully manage natural resources?
A.) Recycling facilities are being constructed around the world.
B.) Underground reserves of oil have not yet been discovered.
C.)Technology that uses natural resources more efficiently are being developed.
D.)The growing human population is putting increasing demands on natural resources.
Answer:
The growing human population is putting increasing demands on natural resources.
Explanation:
In an ecosystem, the most important reason for people to carefully manage natural resources is that the growing human population is putting increasing demands on natural resources.
What is an ecosystem?Ecosystem is defined as a system which consists of all living organisms and the physical components with which the living beings interact. The abiotic and biotic components are linked to each other through nutrient cycles and flow of energy.
Energy enters the ecosystem through the process of photosynthesis .Animals play an important role in transfer of energy as they feed on each other.As a result of this transfer of matter and energy takes place through the system .Living organisms also influence the quantity of biomass present.By decomposition of dead plants and animals by microbes nutrients are released back in to the soil.
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What is the ratio of oxygen to carbon dioxide? 2 C2H6+7 O2=6 H2O+4CO2
Answer:
7:4
Explanation:
The coefficients of a balanced chemical equation give us the mole ratios. The coefficient of carbon dioxide here is 4 and oygen is 7.
How do heatwaves show physical and chemical changes
Answer:
An example of heatwaves showing physical and chemical change is with a burning candle, when a candle burns, there is both a physical and chemical reaction.
The physical change is quite obvious and in fact, it can be seen. When the candle burns, the wax slowly melts and the candle gets smaller and smaller. This wax, as can be seen, will drip onto the candle and stick to it. When this wax forms back into a solid and stays on the candle, that is another physical change that can occur.
The chemical reaction can be a little less obvious. The first is that the heat produced by the candle consumes both the oxygen around it, as well as the fuels coming from the flame. This will then lead to carbon dioxide emissions produced by the flame, which by the way should never be inhaled. This is the chemical change that takes place in the reaction.
Why is the intertidal zone so harsh?
What is the concentration of a solution with a volume of 2.50 liters containing 630. grams of calcium phosphate, Ca3(PO4)2?
Answer:
L=0.85M
Explanation:
ca3 (po4)
66gX1mol/310.18g=2.2178mol/2.5
This transition metal is in group 12 and has less than 34 protons
Zinc (Zn) has less than 34 protons, 30 to be exact, and is a transition metal in Group 12. Note: it is also called a "post-transition metal."
5. Which set of coefficients will balance this chemical
equation?
_C2H4(g) +
O2(g) → 2CO2(g) + 2H2O(g)
A. 1.2
B. 1.3
C. 2.3
D. 2.5
Answer: The answer is B 1,3
During a lab activity students were given samples of four different unknown elements. The students record their observations as shown in the table
Answer:
It is Sample 3, so C
Explanation:
This is because most metals would be solid but this is probualy mercury and it has a pretty low boiling point, and all the other samples are either weak/break easily with a hammer which metals dont do that, and theres a gas, obviously not so if you use process of elimation and common sense, its C
Which of the following pairs of substances form a buffer system for human blood?
A.
HCl and Cl-
B.
NH3 and NH2-
C.
H3C6H5O7 and HC6H5O72-
D.
H2CO3 and HCO3-
Answer:
d. Because those chemicals are easily made when CO2 reacts with water, forming H2CO3 (via carbonic anhydrase
The pairs of substances form a buffer system for human blood is carbonic acid (H₂CO₃) and bicarbonate anion (HCO₃⁻) , Option D
What is a Buffer Solution ?
A buffer is a combination of a weak acid (or base) and a salt that contains the conjugate of that weak acid or base.
A buffer solution is added to maintain the pH of any solution
The buffer of carbonic acid (H₂CO₃) and bicarbonate anion (HCO₃⁻) is used to maintain the balance of acid and base in the body.
It is used to maintain the pH level of the body between 7.35 and 7.45 , as the pH level higher than 7.8 and lower than 6.8 can lead to death.
Therefore the pairs of substances form a buffer system for human blood is carbonic acid (H₂CO₃) and bicarbonate anion (HCO₃⁻) , Option D
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The boiling point of a liquid is the temperature at which its ____________ _____________ is equal to ____________ ____________.(atmospheric pressure, vapor pressure
Answer:
vapor pressure, atmospheric pressure
Explanation:
the boiling point of a liquid is the temperature at which its vapor pressure is equal to the pressure of the gas above it.
(I'm not too sure if this is right but I think it is)
Consider the following representation of a reaction mechanism.
Step 1: A+A → C+E (slow)
Step 2: E + B → A+D (fast)
Overall reaction: A + B → C + D
What should appear in the rate law for the reaction above?
A) only A and B because they are reactants in the overall reaction
B) only C and C because they are products in the overall reaction
C) only A because it is the reactant in the rate-determining step
D) only E and B because they are the reactants in the rate-determining step
Can someone help its confusing
Answer:
It's a metaphor. It's comparing Jordan and their emotions to a tornado
About what percent of the Earth is covered in salt water oceans?
A.84%
B.71%
C.49%
D.65%
Answer:
B
Explanation:
(b) Which solution has a higher percent ionization of the acid, a 0.10M solution of HC2H3O2(aq) or a 0.010M solution of HC2H3O2(aq) ? Justify your answer including the calculation of percent ionization for each solution.
Answer: The percent ionization is higher for 0.010 M solution of [tex]HC_2H_3O_2[/tex]
Explanation:
[tex]HC_2H_3O_2\rightarrow H^+C_2H_3O_2^-[/tex]
cM 0M 0M
[tex]c-c\alpha[/tex] [tex]c\alpha[/tex] [tex]c\alpha[/tex]
So dissociation constant will be:
[tex]K_a=\frac{(c\alpha)^{2}}{c-c\alpha}[/tex]
a) Given c= 0.10 M and [tex]\alpha[/tex] = ?
[tex]K_a=1.8\times 10^{-5}[/tex]
Putting in the values we get:
[tex]1.8\times 10^{-5}=\frac{(0.10\times \alpha)^2}{(0.10-0.10\times \alpha)}[/tex]
[tex](\alpha)=0.013[/tex]
[tex]\%(\alpha)=0.013\times 100=1.3\%[/tex]
b) Given c= 0.010 M and [tex]\alpha[/tex] = ?
[tex]K_a=1.8\times 10^{-5}[/tex]
Putting in the values we get:
[tex]1.8\times 10^{-5}=\frac{(0.010\times \alpha)^2}{(0.010-0.010\times \alpha)}[/tex]
[tex](\alpha)=0.041[/tex]
[tex]\%(\alpha)=0.041\times 100=4.1\%[/tex]
The percent ionization is higher for 0.010 M solution of [tex]HC_2H_3O_2[/tex]
intrusive igneous rock forms when the cooling of magma takes place fast on the top of the Earth's surface. A. True B. False
Answer:
A
Explanation:
True igneous rock forms cooling of magma fast on the top
Answer:
The answer is A. True
Explanation:
Use the information and table to answer the following question.
Scientists use either a melting år freezing point apparatus to determine the melting points of the following unknown compounds as part of
their investigation. Based on the melting points, the scientists determine the bond type and record the results in the table as shown.
Unknown Compound
Compound 1
Exhibits
Compound 2
Compound 3
Compound 4
Melting Point
772°C
17°C
960°C
-56°C
Which statement correctly identifies the ionic compounds and why?
A Compounds 1 and 3 are lonic. Because covalent compounds are composed of oppositely charged ions that are attracted to one
another, they require more energy to melt than ionic bonds.
O B. Compounds 2 and 4 are ionic. Because covalent compounds are composed of oppositely charged ions that are attracted to one
another, they require more energy to melt than ionic bonds.
C. Compounds 2 and 4 are ionic. Because ionic compounds are composed of oppositely charged ions that are attracted to one another,
they require more energy to melt than covalent bonds,
D. Compounds 1 and 3 are ionic. Because ionic compounds are composed of oppositely charged ions that are attracted to one another,
they require more energy to melt than covalent bonds.
Answer:
Explanation:
are you doing your mid term?well i got c
Answer:
D
Explanation:
Compounds 1 and 3 are lonic.Because ionic compounds are composed of oppositely charged ions that are attracted to one another,
they require more energy to melt than covalent bonds. just usign he process of elimination you get rid of A and B becuase covalant compound contaIN same negatively charged particles that contain requrie less energy to melt and since two and four have low melting point its d
Dihydrogen sulfide reacts with oxygen gas to form sulfur dioxide and water. How many moles of oxygen gas will react when 0.6469 moles of water are formed?
Answer: 0.9704 moles of [tex]O_2[/tex] will react when 0.6469 moles of water are formed.
Explanation:
The balanced chemical reaction is:
[tex]2H_2S+3O_2(g)\rightarrow 2SO_2+2H_2O[/tex]
According to stoichiometry :
2 moles of [tex]H_2O[/tex] are formed from = 3 moles of [tex]O_2[/tex]
Thus 0.6469 moles of [tex]H_2O[/tex] are formed from =[tex]\frac{3}{2}\times 0.6469=0.9704moles[/tex] of [tex]O_2[/tex]
Thus 0.9704 moles of [tex]O_2[/tex] will react when 0.6469 moles of water are formed.
When does the object change direction?
Distance vs. Time
50
40
30
20
10
c
D
2
6
8
10
Time
F
Answer:
50distance and 10minutes time
Explanation:
because it's the best object
When ammonium chloride crystals are dissolved in water, the temperature of the water decreases. What does the temperature change indicate about the dissolving of ammonium chloride in water.
Answer:
See Explanation
Explanation:
A decreasing temperature indicates that the dissolution process for the ammonium chloride requires input of energy from surroundings. That is, the process is essentially 2 parts => system (object of interest - NH₄Cl) and the surroundings (everything else - solvent - H₂O). The surroundings (water) solvent is showing a measured decrease in temperature or loss of energy (exothermic to surroundings) which flows into the system (NH₄Cl) and effects dissolution of salt into solution (endothermic to system).
What is the definition of a Double Displacement Reaction?
Answer:
A double displacement is a type of chemical reaction that in which the reactant ions exchange places to form new products
Explanation:
I took the quiz
Answer:
When two different atoms or groups of atoms are exchanged, then it is a double displacement reaction.
Which of these pure substances do you think are Elements?
Au (Gold)
C6H12O6 (Sugar)
Fe (Iron)
NaCl (Salt)
O (Oxygen)
Fe2O3 (Rust)
What is the weight percentage of NaOH?
why do men
thats it that’s the question
Explanation:
babe I wish I knew I would tell you
Answer:
Not all men are like this. It depends on how they were raised
Which of the following (H+) values describes a neutral solution?
O 10-1M
O 10-7M
10-14 M
O 10-12M
Answer:10-^7M
Explanation: this is a neutral solution as the [H+] and [OH-] is of same value ie,10-^7M