Answer:
Knowing how elements and compounds react together is essential in everyday life is essential to people like a scientist and someday you might become a scientist no matter what you become you will have to learn all that you can.
UwU Hope I helped
Answer:
it is very important to know how elements and compounds react together because everything that surrounds us is made out of elements and compounds. Therefore, understanding how these work can allow us to have a better understanding of the world that surrounds us. Moreover, it can avoid accidents when we deal with dangerous compounds, such as when we cook or clean
Explanation:
group viia elements are very active non metals give reason
Answer:
because they need only one electron
How does heat from the sun turn liquid water into gas called water vapor?
Answer:
Explanation:Once energy is added to water by heat from the sun, the bonds between the water molecules gain kinetic energy or energy in motion. Then they escape the surface of the liquid and become a gas (water vapor), which rises into atmosphere.
The specific heat of iron is 0.46 J/g°C. How many joules will it take to make the temperature of a 150. g bar go up from 25°C to 60.°C?
Answer:
Q = 2.415kj
Explanation:
Q = Mc∆temperature
c = 0.46j/g°c = 0.46kj/kg°c
mass = 150g = 0.15kg
∆temperature = 60 - 25 = 35°c
Q = 0.15 X 0.46 X 35 = 2.415kj
Q = 2.415kj
Does the following equation follow the law of conservation of mass? Show your work
AgNO3 → Ag2 + NO3
Answer:
No.
Explanation:
If the equation follows the law of conservation of mass, then the amount of reactants must be equal to the amount of products. That is not the case for the provided equation due to 1 Ag on the reactants side versus 2 Ag on the products side.
Select all the correct answers.
In this reaction, how does the rate of forward reaction vary with the concentration of the product?
2H,S() =2H() + S(g)
O It increases with an increase in the concentration of S-(g).
OIt decreases with a decrease in the concentration of H().
OIt increases with a decrease in the concentration of H-(g).
It decreases with an increase in the concentration of S,().
It decreases with increase in the concentration of Ha().
The correct answers :
It increases with a decrease in the concentration of H₂(g).
It decreases with an increase in the concentration of S₂(g).
It decreases with an increase in the concentration of H₂(g).
Further explanationForward reaction : rate to form product
In equilibrium :
The product decreases ⇒ system will move from left to right(forward reaction)
The product increases ⇒ system will move from right to left(reverse reaction)
can someone help me with the unanswered questions pls sorry about bad quality
Answer:
I cant see it sorry
Explanation:
One can find the pH of a substance by using ___.
A. a conductivity tester
B. a thermometer
C. plain paper indicator
D. litmus paper indicator
Explanation:
C. Plain paper indicator.
Litmus paper indcator can only tell you if the solution is acidic/neutral/alkaline, but not to what extent.
What is the difference between a plain and a plateau? A. Only a plain is flat, a plateau is steep mountainside. B. Both are flat, but a plateau is bordered by cliffs. C. A plain is rolling hills with cliffs, and a plateau is large flat area.
Answer:
B
Explanation:
Both plain and plateau have flat surfaces. However, a plain is located in a low-lying area while a plateau is located on an elevated area. In essence, a plateau can be viewed as an elevated plain or a plain that is bordered by cliffs.
The correct option is B.
(0)A mixture of dihydrogen and dioxygen at one bar pressure contains 70% by weight of dioxygen. Calculate the partial pressure of dioxygen.
a (ii)Calculate the volume occupied by 8.8 g of CO2 at 31.1°C and 1 bar pressure. R = 0.083 bar L K-1 mol-1
Answer:
a) 0.13 bar
b) 5.05 L
Explanation:
Let us take the mass of the mixture to be 100 g. Hence, 70% by weight of dioxygen corresponds to 70 g
Mass of dihydrogen = 100g - 70 g = 30g
Number of moles of dioxygen = 70g/32 g/mol = 2.2 moles of dioxygen
Number of moles of dihydrogen = 30g/2g/mol = 15 moles of dihydrogen
Total number of moles = 2.2 + 15 = 17.2 moles
Mole fraction of dioxygen = 2.2/17.2 = 0.13
Partial pressure = mole fraction * total pressure
Partial pressure of dioxygen = 0.13 * 1 = 0.13 bar
ii) number of moles in 8.8 g of CO2 = 8.8g/44g/mol = 0.2 moles
T = 31.1 + 273 = 304.1 K
P = 1 bar
V= ?
R = 0.083 bar L K-1 mol-1
From
PV=nRT
V = nRT/P
V= 0.2 * 0.083 * 304.1/1
V= 5.05 L
At night, the demand for electricity supplied by a fission nuclear reactor decreases. How is the fission nuclear reaction controlled to avoid overproduction of electricity? The temperature of the reactor is lowered because high temperature and pressure are needed. The temperature of the reactor is raised because the reaction slows down at higher temperatures. The exposure between the fuel rods and a neutron-absorbing material is increased. The exposure between the fuel rods and a neutron-absorbing material is reduced.
Answer:
The exposure between the fuel rods and a neutron-absorbing material is increased.
Explanation:
The exposure between the fuel rods and a neutron-absorbing material is increased.
A nuclear reactor produces energy via a fission reaction. A fission reaction is a self sustaining reaction.
The nuclear fuel is bombarded with neutrons. The process produces more neutrons which continues the reaction.
In order to decrease the rate of reaction, control rods are inserted. These control rods are neutron-absorbing materials.
At night when demand for electricity decreases, the exposure between the fuel rods and a neutron-absorbing material is increased so that more neutrons are absorbed in order to decrease the rate of nuclear reaction.
A 30 kg wrecking ball was dropped from different heights.
30 kg Wrecking ball
Height dropped
Speed at impact
Energy at impact
Distance Object is moved
Trial 1
5m
9.9 m/s
1470 J
0 cm
Trial 2
7m
11.71 m/s
2058 J
3 cm
Trial 3
15m
17.15 m/s
4410 J
55 cm
Trial 4
25m
22.14 m/s
7350 J
120 cm
What is the relationship between drop height and energy at impact?
MARKING BRAINLIEST!
Many processes occur in the digestive system. Which process is best classified as a physical change?
A. digestive enzymes breaking down proteins into smaller fragments
B. teeth grinding an almond into smaller pieces in the mouth
C. bacteria converting lactose into simple sugars in the intestines
D. saliva converting the starch molecules in crackers into simpler sugars
Answer:
Teeth gridning
Explanation:
BC YOUR GRINDING IT
sandy is looking though a stanstance that that absorbs some of the light waves and others others through. what type of light transmission is sandy seeing?
A. Translucent
B. opaque
C. transparent
D. a substance with color
Answer:
A. Translucent
Explanation:
Sandy is seeing a light transmission through a translucent medium. Or we can say this is a translucent light transmission.
In a translucent light transmission, some of the light are allowed to pass through and some are cut off. An example is frosted glass, tinted glassAn opaque object is does no allow any light to pass through. It simply does no transmit light. An example is paper, leaf and a bookA transparent transmission allows all of the light to pass through.how many grams of hydrogen are required to react completely with 400g nitrogen to form ammonia? Pls help
N2+3H2-->2NH3
first we find the number of nitrogen moles
the molar mass for N2 is 14+14=28g/mole
to find the number of moles we divide the mass by the molar mass
n=400/28=14.28 moles
for 1 mole of N2 we use 3 moles of H2, therefore for 14.28 moles of N2 we use 14.28*3=42.84 moles ofH2
to find the mass of H2 we multiply the number of moles by the molar mass
the molar mass of H2 is 2g/mole
2*42.84=85.68g of H2
If there is less ionization energy does that mean that it is more reactive? Why?
Answer:
The greater the ionization energy, the more difficult it is to remove an electron. The ionization energy may be an indicator of the reactivity of an element. Elements with a low ionization energy tend to be reducing agents and form cations, which in turn combine with anions to form salts.
What are food molecules made out of?
Answer:
Most foods are made out of carbon, oxygen, nitrogen and hydrogen
Explanation:
Please answer this...
A. 207 kJ
B. 4730 kJ
O C. 9460 kJ
O D. 414 kJ
Answer:
C = 9460 Kj
Explanation:
Given data:
Mass of copper = 2kg
Latent heat of vaporization = 4730 Kj/Kg
Energy required to vaporize 2kg copper = ?
Solution:
Equation
Q= mLvap
by putting values,
Q= 2kg × 4730 Kj/Kg
Q = 9460 Kj
x-rays had a frequency of about 3x10^18 determine it's wavelength (in nm) and energy per photon
Answer:
E = 19.89×10⁻¹⁶ J
λ = 1×10⁻¹ nm
Explanation:
Given data:
Frequency of xray = 3×10¹⁸ Hz
Wavelength of xray = ?
Energy of xray = ?
Solution:
speed of wave = wavelength × frequency
speed = 3×10⁸ m/s
3×10⁸ m/s = λ ×3×10¹⁸ s⁻¹
λ = 3×10⁸ m/s / 3×10¹⁸ s⁻¹
λ = 1×10⁻¹⁰m
m to nm:
λ = 1×10⁻¹⁰m×10⁹
λ = 1×10⁻¹ nm
Energy of x-ray:
E = h.f
h = plancks constant = 6.63×10⁻³⁴ Js
by putting values,
E = 6.63×10⁻³⁴ Js ×3×10¹⁸ s⁻ ¹
E = 19.89×10⁻¹⁶ J
The table below shows the elements that mainly comprise each of the four layers of Earth:
Elements in Layers
Layer Main Elements
Crust Oxygen, Silicon
Mantle Iron, Magnesium
Outer Core Iron, Nickel
Inner Core Iron
Which of these elements make up the layer that is 0.2 to 1.1 percent of Earth's total diameter?
Magnesium and Silicon
Iron and Magnesium
Iron and Nickel
Oxygen and Silicon
Answer:
The answer is oxygen and silicon
Explanation:
I took the test and it was right
The answer is oxygen and silicon
Why does a chemical equation be balanced?
Answer:
Law of conservation of matter
Explanation:
What contribution did Niels Bohr make to atomic theory
Answer:
Bohr's greatest contribution to modern physics was the atomic model. The Bohr model shows the atom as a small, positively charged nucleus surrounded by orbiting electrons.
Explanation:
Answer: He proposed a theory for the hydrogen atom based on quantum theory
Explanation:
100 cm3 of hydrogen is mixed with 25 cm3 of oxygen at a temperature of 150qC. The gases react as shown in the equation below. 2H2(g)+ O2(g) o 2H2O(g) The total volume of gas present at the end of the reaction is A 50 cm3 B 100 cm3 C 125 cm3 D 150 cm
Answer:
B 100 cm3
Explanation:
The balanced equation is given as;
2H2(g)+ O2(g) --> 2H2O(g)
From the reaction stochiometry, 2 cm3 of H2 would react with 1 cm3 of O2 to form 2 cm3 of H2O
Before Reaction --> 100cm3 of H2, 25cm3 of O2, 0cm3 of H2O
During Reaction --> 50cm3 of H2, 25cm3 of O2, 50cm3 of H2O
(Oxygen is sed uup in the reaction)
After Reaction --> 50cm3 of H2, 0cm3 of O2, 50cm3 of H2O
Total volume left = Unreacted H2 (50cm3) + 50cm3 of H2O formed
Total Volume left = 50 + 50 = 100cm3
The total volume of gas present at the end of the reaction is 100 cm³
What is a chemical reaction?a process that involves rearrangement of the molecular or ionic structure of a substance, as distinct from a change in physical form or a nuclear reaction.
The balanced equation is given as;
2H₂(g)+ O₂(g) → 2H₂O(g)
From the reaction stoichiometry, 2 moles of H₂ would react with 1 mole of O₂ to form 2 moles of H₂O
Before Reaction: 100cm³ of H₂, 25cm³ of O₂, 0cm³ of H₂O
During Reaction: 50cm³ of H₂, 25cm³ of O₂, 50cm³ of H₂O
(Oxygen is used up in the reaction)
After Reaction: 50cm³ of H₂, 0cm³ of O₂, 50cm³ of H₂O
Total volume left = Unreacted H₂ (50cm³) + 50cm³ of H₂O formed
Total Volume left = 50 + 50 = 100cm³
Hence, The total volume of gas present at the end of the reaction is 100 cm³
To learn more about chemical reactions, click here:
https://brainly.com/question/6876669
1. A group of elements that includes the most active of the nonmetals is the
a. nitrogen group.
c. noble gases.
b. alkaline earths.
d. halogens.
Answer:
D. Halogens
Explanation:
All elements in these groups have 7 valence electrons, meaning their electronegativity is the highest among the elements.
The recessive allele tends to (blank) when it's in the presence of the dominant allele.
Answer:
The recessive allele tends to be masked when it's in the presence of the dominant allele.
Explanation:
Many of our traits are affected by our genes. From each of our parents, we receive one copy of every gene. These copies are called alleles.
There are different types of relationships that can occur between alleles. One of them is called dominance. This occurs when one allele masks the other, not allowing its effect to be expressed. The allele that masks the other is called the dominant allele (A), and the masked one is called the recessive allele (a). This means that an individual needs to have only one dominant allele in order for its effect to be expressed (AA or Aa). The effect of the recessive allele will be expressed only when an individual has both recessive alleles (aa).
(30 points) Ahhhhhhh can someone help me :'))
I'm not smart and I don't understand how to solve this problem:
Octane, one of the major components of gasoline, burns in air according to this unbalanced equation:
C₈H₁₈ (l) + O₂ (g) ----> CO₂ (g) +H₂O
The formula balanced is: 2 C₈H₁₈ (l) + 50 O₂ (g) ----> 16 CO₂ (g) + 18 H₂O
a) What volume of O₂ at STP is needed to burn 702g (1.00L) of octane?
b) What volume of O₂ at 18°C and 0.975 atm is needed to burn 702g of octane?
Answer:
a. 137.93 dm3
b. 150.61 L
Answer:
C₈H₁₈
Explanation:
Clay and Pumice have pores but the pores are not well connected. If you poured water over either of them it would just run off the surface. It wouldn't run through. But they could hold water in their pores. We can say then that both or them ARE ___________________ but NOT __________________________________.
Answer:
Clay and Pumice can both be said to be Porous but they are not Permeable
Explanation:
A porous substance is one which have pores in in through which air or liquid can pass through. Both clay and pumice are porous due to the presence of pores in them. These pores allow air to pass through them. However, since the pores are not well connected water do no pass through them. As a result, clay vessels can hold water within them and pumice floats on water.
Permeability is the ability of a substance to allow other substances to pass through. Both clay and pumice have low permeability, as a result they do not allow water to pass through them. Rather, water runs over their surface when poured over them.
Answer:
Clay and Pumice can both be said to be Porous but they are not Permeable
Explanation:
Oil and water placed in a jar will separate. Even when shaken and mixed, the oil still separates from the water.
Which best describes oil and water?
Oil and water are highly soluble because they have separate chemical properties.
Oil and water have a low solubility because they have separate chemical properties.
Oil and water are highly soluble because they exert different pressures.
Oil and water have a low solubility because they exert different pressures.
Answer:
Probably B?
Explanation:
I don't have one...
Hope it helps I guess..
Answer: i think is B
Explanation: HATE ME IF IM WRONG
#1 - What is a pure substance? *
1 point
two or more atoms held together by chemical bonds
the attractive force that holds atoms together
a sample of matter that has specific chemical and physical properties
a pure substance made up of two or more different types of atoms joined by chemical bonds
#2 - TRUE OF FALSE: Water is a pure substance.
1 point
True
False
#3 - What is an atom? *
1 point
the smallest unit of an element that keeps the properties of that element
the attractive force that holds atoms together
a sample of matter that has specific chemical and physical properties
a pure substance made up of two or more different types of atoms joined by chemical bonds
#4 - What is a molecule? *
1 point
two or more atoms held together by chemical bonds
the attractive force that holds atoms together
a sample of matter that has specific chemical and physical properties
a pure substance made up of two or more different types of atoms joined by chemical bonds
#5 - What is a chemical bond? *
1 point
two or more atoms held together by chemical bonds
the attractive force that holds atoms together
a sample of matter that has specific chemical and physical properties
a pure substance made up of two or more different types of atoms joined by chemical bonds
#6 - TRUE OR FALSE: Molecules are all the same size. *
1 point
True
False
#7 - What is a compound? *
1 point
two or more atoms held together by chemical bonds
the attractive force that holds atoms together
a sample of matter that has specific chemical and physical properties
a pure substance made up of two or more different types of atoms joined by chemical bonds
#8 - TRUE OR FALSE: Compounds never form in a fixed ratio. *
1 point
True
False
#9 - TRUE OR FALSE: The structure of matter at the atomic and molecular levels is too small to observe directly. *
1 point
True
False
#10 - TRUE OR FALSE: A complex molecule may contain a few atoms bonded together. A simple molecule may contain thousands of atoms. *
1 point
True
False
#11 - What is a crystal? *
1 point
two or more atoms held together by chemical bonds
a substance in which the particles are arranged in an orderly, geometric, and repeating pattern
a sample of matter that has specific chemical and physical properties
a pure substance made up of two or more different types of atoms joined by chemical bonds
#12 - TRUE OR FALSE: Diamond and graphite are both made of carbon atoms. *
1 point
True
False
Answer/Explanation:
#1 - A pure substance is either an element or a compound, making it different from a mixture. A sample of matter that has specific chemical and physical properties is the only one that fits here.
#2 - A pure substance is either an element or a compound, making it different from a mixture. Water is a compound, and thus this would be true.
#3 - An atom is the smallest unit of an element that keeps the properties of that element. Just refer to its definition.
#4 - A molecule is two or more atoms held together by chemical bonds . Again, just refer to its definition.
#5 - A chemical bond is the attractive force that holds atoms together . Jus refer to its definition.
#6 - Molecules are most definitely not all the same size, especially given the huge number of them. This would be false.
#7 - A compound is a pure substance made up of two or more different types of atoms joined by chemical bonds . Just refer to its definition.
#8 - Compounds always form in a fixed ratio, so this would be false.
#9 - If by directly, the problem means with the naked eye, this would be true.
#10 - False. It's reversed.
#11 - A crystal is a substance in which the particles are arranged in an orderly, geometric, and repeating pattern . Just refer to its definition.
#12 -True; to be more specific, they are covalent network solids.
3. What determines that an element is a metal?
Answer:
if it forms from positive ions and has types of metallic bonds
Explanation:
