Answer:
The excretory system removes waste from the body. remove waste from the blood. The digestive system breaks down the food you eat into nutrients that provide energy and building materials for cells. The digestive and excretory sytems work together to process the food that you eat.
Explain how heat is conducted along a metal bar.
It causes the particles to vibrate and this causes the neighbouring particles to vibrate.
this process is continued until particles at the other vibrates.hence heat is transmitted from one place to another .Also it causes electrons to collide with the atoms of the metal.
Which of the following statements about alcohols is false?
A. Ethanol is soluble in water.
B. Ethanol has a higher boiling point than ethane.
C. Ethanol produces hydrogen when it burns.
D. None of these
Answer:
It's C. Ethanol produces hydrogen when it burns
When burned, ethanol produces water and CO2.
How many nickels are there in $5.25?
Answer:
105
Explanation:
1 nickel = 5 cents
5.25 dollars x 100 cents
= 525 cents
525 cents / 5 cents
= 105 nickels
If an object is travelling 25.0 meters/second, how long will it take to travel 1.5 km?
Answer:
60 sec
Explanation:
in 1.5km there is 60 unit of 25 meter so
When scientists talk about mass and volume, they are talking about which
of these?
A. energy
B. heat
C. matter
D. a vacuum
Answer:
C. Matter
Explanation:
Answer:
C. Matter
Explanation:
Matter is anything that occupies space(volume) and has mass.
GIVING 20 POINTS!! Apply Concepts Two chemists each plan an investigation in which they will combine hydrogen gas with chlorine gas to observe the chemical reactivity. The plans differ in that one will use 25 milligrams each of hydrogen and chlorine, and the other will use 1000 times this amount, i.e., 25 grams each of hydrogen and chlorine. Can the investigations reach similar conclusions about the reactivity of hydrogen with chlorine? Explain.
Answer:
Yes, the investigations will reach similar conclusions about the reactivity of H2 and Cl2
Explanation:
1. The law of multiple proportions says that when elements form compounds, the proportions of the elements in those chemical compounds can be expressed in small whole number ratios. This means that regardless of whether 1000 times more of the products are used, the reactivity of the products is established by the chemical reaction
2. The law of multiple proportions is an extension of the law of definite composition, which states that compounds will consist of defined ratios of elements.
3. A reaction with more reactants will need more care because more products are produced, which can be toxic
4. H2 and Cl2 reactivity does not depend on the quantities but the chemical properties of each compound
1. Lanthanides and actinides are kept separately in the modern periodic table. Why?
2. Differentiate between long period and short period in any two points.
- Help!! Random / Plagiarised answers will be reported! *
Answer:
1.. Lanthanides and actinides are kept separately in the modern periodic table Why?
Lanthanides and actinides are kept separately in the modern periodic table because of following reason:
If they are placed in the body of the periodic table, the periodic table will become extremely long and hard to recognizemore scientific and technical reason why they chose to keep the lanthanides and actinides away from the rest of the periodic table was to help in the grouping of elements in blocksExplanation:
2. Differentiate between long period and short period in any two points.
Long period:
The 4th and 5th periods of the periodic table are called long periods. The long periods coontain 18 elements in themshort period:
The 2nd and 3rd periods of the periodic table are called short periods. The short periods contain 8 elements in them5
Which of the following is true regarding the particle nature of a solid?
Particles in a solid -
A
move very little, so it cannot easily change its shape.
B
are relatively far apart, so it is highly compressible.
с
are in continual motion, and can slide past each other.
D
are very far apart, so it can easily change its shape.
Answer:
this answer is b no u can it very easy
Explanation:
because solid and liquid can compress easily
plz support me
Answer:
A. move very little, so it cannot easily change its shape.
Which list includes terms that only describe carbon dioxide, (CO2)?
a
molecule, compound, mixture
b
molecule, compound, pure substance
c
atom, element, mixture
d
atom, element, pure substance
Answer:
b. molecule, compound, pure substance
Terms that only describe carbon dioxide are molecule, compound, pure substance.
What is mixture and compound?In chemistry mixture is a combination of two or more different chemical elements which are not chemically bond. A mixture is the physical composition of two or more elements in which their individual identities are vanished and it also mixed by solutions, suspension and colloids.A compound can't be separate by physical separation and after the mixture you can't identified that it is compound or not.
In chemistry compound is combination of two or more different elements which are chemically bond. So compound is made up of chemical bond. A compound can't be separate by physical separation and after the mixture you can't identified that it is compound or not.A mixture is the physical combination of two or more elements in which their individual identities are retained and it also mixed by solutions, suspension and colloids.
Therefore, terms that only describe carbon dioxide are molecule, compound, pure substance.
Learn more about compound and mixture here:
https://brainly.com/question/5169457
#SPJ2
How many moles of water are in 1.23x10^18 water molecules?
in scientific notation
Answer:
1.23x10^24 atoms/6.022x10^23 atom/mol = 2.04 mol H20
Explanation:
Can someone please help me out !!!
Explanation:
Volume = FL - SL
= 39 - 33
= 6
How does an atom change if all of its electrons are removed?
How does an atom change if all of its electrons are removed?
The atom’s volume increases.
The atom’s mass increases.
The atom becomes positively charged.
The atom becomes negatively charged.
Answer:
c
Explanation:
it becomes positively charged
Answer:
The atom becomes positively charged.
Explanation:
If ALL OF THE ELECTRONS are removed, then there are, no matter what, less electrons than protons in an atom. And, since the atom has less electrons than protons, it becomes positively charged.
What are the missing coefficients for the chemical equation
[ ] C2H2 + [ ] O2 → [ ] CO2 + [ ] H2O
Answer:
2C2H2 + 5O2 → 4CO2 + 2H2O
Explanation:
Plzzzzzz help me Write electronic configuratof sodium and chlorine in the term of subshell ?
Answer:
ans:Ne=2,8,1
ans:2,8,7
If aluminium has an atomic number of 13and has 14 neutrons what is its mass number
Answer:
27
Explanation:
mass number A = atomic number z + number of neutrons = 13+14= 27
Answer:
Explanation:
27
sound travels at 331m/s. How long would it take for sound to travel across lake tahoe, which is 21.6 miles long
Answer:
It would take sound 104.998 seconds to travel across lake tahoe.
Explanation:
First let's convert the miles to meters, so, 21.6 miles = 34754.4 meters
Now, we will divide this number in meters by 331. So, 34754.4 / 331 = 104.998
And what will the unit be? Seconds will be the unit for time here so 104.998 seconds.
If I have 4.9 moles of gas at a pressure of 2.0 atm and a temperature of 56 Celsius, what is the volume of the cantainer that the gas is
in? (R=0.0821 L*atm/mol*K)
Answer: 132 liters. or 130 liters with 2 sig figs.
Explanation: Use the ideal gas law: PV = nRT
We want V, so rewrite and plug in data:
Temperture must be in Kelvin (add 273.15 to
V = (nRT)/P
V = (4.9 moles)*(0.0821 L*atm/molK)*(328.2K)/(1atm)
V = 132 liters (3 sig figs). 130 liters with 2 sig figs
What is 3 x 10^4 multiplied by 5 x 10^2?
Answer:
15000000
Explanation:
30000 x 500=15000000. I believe... lemme know if I was wrong, hope this helps <3.
PLEASE HELP ON EASY CHEMICAL PROPERTIES
Answer:
1, just I) color.
Explanation:
Physical properties are the properties that can be observed without changing the composition of a substance, such as color, temperature, density, and boiling point.
A physical change is a change in the substance that only modifies its aggregation state, such as solidification, and boiling.
Chemical properties are the properties that need a reaction to being observed, such as combustibility, which needs a combustion reaction to being quantified.
When a chemical reaction occurs, and the composition of the substance change, it's a chemical change.
So, heating copper with carbon is a chemical reaction, and purification by electrolysis is too. Color is the only physical property.
PLEASE HELP ASAP !!! WILL GIVE BRAINLIEST
What were the changes to the atomic model over time?
Answer:
The atomic model started out as a large single ball, then with electrons attached to it. It then became "planetary model" with electrons orbiting at specific levels, and then later one with a nucleus or multiple different particles like protons and neutrons, and electrons orbiting at general (but not specifically predictable) areas.
Explanation:
thank u :)
Which two elements have the same number of energy levels with electrons in them?(1 point)
A_ krypton and neon
B_ boron and oxygen
C_ lithium and francium
D_ neon and sodium
Its B) Boron and Oxygen
The correct answer is B.
boron and oxygen have the same number of energy levels with electrons in them.
The energy level of an element is the region around the nucleus where its electron is likely to be, this corresponds to the period of the element in the periodic table.
Elements found in period 1, have one energy level.
Elements found in period 2, have two energy level.
Examples of elements found in period 2 include:
lithium, beryllium, boron, carbon, nitrogen, oxygen, fluorine, and neonIn the given options, only option B contains two elements with 2 energy level.
Thus, boron and oxygen have the same number of energy levels with electrons in them.
Learn more here: https://brainly.com/question/18616411
If you can run 6km in 24 minutes, how many cm can you run in 5 hours?
Answer:
7500000cm/hr
Explanation:
6km=600000cm
24min=24/60hr=0.4hr
so, according to the question
6k/24km=600000cm÷0.4hr
=1500000cm/hr
therefore in 5 hours we can run:
5×1500000cm/Hr
=7500000cm/hr
A person can run "7,500,000 cm" in 5 hours.
According to the question,
A person can run 6 km in 24 minutes, i.e.,
= [tex]\frac{6}{24} \ km/min[/tex]
and,
5 hours = 300 minutes
then,
→ A person can run in 5 hours:
= [tex]\frac{6}{24}\times 300[/tex]
= [tex]\frac{1800}{24}[/tex]
= [tex]75 \ km[/tex]
By converting km into cm, we get
= [tex]7500000 \ cm[/tex]
So the above is the right answer.
Learn more:
https://brainly.com/question/19035673
Mi One should know the properties of the components of the mixture to separate it. Explain with an example.
What is the Color of trioxonitrate(v)
Answer:
it's yellowish in color plz Mark me as brainliest
Answer:
It's a yellowish color like copper
The atomic number of the element with the maximum number of unpaired 2p electrons in the ground state is
1) 1 2) 7 3) 13 4) 8
Water from this pot is changing from a liquid to a steam. Which process is taking place?
A. condensation
B. Boiling
Answer:
Boiling B.
Explanation:
What is the name of this ??
Answer:
Explanation:
Your answer is C
Someone plz help me :(
Answer:
B and A.
Explanation:
Many of the great scientists were religious. But the answer is not D.
A scientist may have strong opinions. That was certainly true of Newton. Most of the time he was right. Still the answer is not C. Science requires an open mind.
The answer is between A and B. Many discoveries were made looking at the natural world. That may provide the inspiration. But I don't think it is the answer. I'm going to say A
B is the other answer. Between A and B many scientific truths have been discovered.
what is the mass of 0.2 moles of ethanol
Answer:
Answer is 9.2 grams
Explanation:
Molar mass of ethanol
[tex]{ \bf{CH _{3}CH_{2}OH}} = (12 \times 2) + (6 \times 1) + (16) \\ = 46 \: g[/tex]
for moles:
[tex]{ \sf{1 \: mole \: of \: ethanol \: weighs \: 46 \: g}} \\ { \sf{0.2 \: moles \: weigh \: (0.2 \times 46) \: g}} \\ = 9.2 \: g[/tex]
A compound contains only carbon, hydrogen, and oxygen. Combustion of 8.544 mg of the compound yields 12.81 mg CO2 and 3.50 mg H2O. The molar mass of the compound is 176.1 g/mol. What are the empirical and molecular formulas of the compound
Answer:
The empirical formula is the formula with a minimum whole number ratio of the constituent atoms present in a molecule. While the molecular formula has the actual number of atoms of various elements present in the molecule of the substance.
Empirical formula is C₃H₄O₃
Molecular formula is C₆H₈O₆
This question involves finding the empirical and molecular formulas. Empirical formula is the one where minimum whole number ratio of the constituent atoms present in a molecule is shown whereas molecular formula is the one that shows the number of each type of atom that are present in a molecule.The compound contains only carbon, oxygen and hydrogen and undergoes combustion. Thus;[tex]C_{x}[/tex][tex]H_{y} O_{z}[/tex] + O₂ ⟶ xCO₂ + [tex]\frac{y}{z} H_{2} O[/tex]
The combustion yields 12.81 mg of CO₂.From online sources, molar mass of CO₂ = 44 g/mol
number of moles of CO₂ = 12.81/44 = 0.291m mol
Mass of carbon in it is; C = 12 × 0.291 = 3.492 mg
Similarly the combustion yields 3.50 mg H2O.molar mass of water = 18 g/mol
number of moles of water in it = 3.5/18 = 0.194m mol
Hydrogen has 2 nos in water and so;
number of moles of hydrogen = 2 × 0.194 = 0.388m mol
Mass of hydrogen = 1 × 0.388 = 0.388 mg
Compound is 8.544 mg and so;Oxygen mass = 8.544 - (3.492 + 0.388) = 4.664 mg
Similarly, moles of oxygen that has molar mass of 16 is;
no of moles of oxygen = 4.664/16 = 0.2915m mol
Thus;Ratio of C:H:O is; 0.291:0.388;0.2915
Simplifying this gives us the empirical formula ratio as;
3:4:3
Thus;
Empirical formula is C₃H₄O₃
Molar mass of C₃H₄O₃ = (12 × 3) + (1 × 4) + (16 × 3) = 88 g/molWe are told that the molar mass of the compound is 176.1 g/mol.
Thus;
Molecular formula is; (176.1/88)C₃H₄O₃ = C₆H₈O₆
Read more at; brainly.com/question/14853529