Answer:
1. oxygen gas
2. Asteroid and comet bombardment had
increased
3. A secondary atmosphere is an atmosphere of a planet that did not form by accretion during the formation of the planet's star. A secondary atmosphere instead forms from internal volcanic activity, or by accumulation of material from comet impacts.
The climate of the Quaternary period showed several decreases in global temperature (glacial periods) separated by warm (interglacial) periods. Core samples taken from sea beds elude to at least sixteen glaciations during the Quaternary period.
A primary atmosphere is an atmosphere of a planet that forms by accretion of gaseous matter from the accretion disc of the planet's sun. Planets such as Jupiter and Saturn have primary atmospheres. Primary atmospheres are very thick compared to secondary atmospheres like the one found on Earth.
Now we have Earth's “third atmosphere,” the one we all know and love—an atmosphere containing enough oxygen for animals, including ourselves, to evolve. So plants and some bacteria use carbon dioxide and give off oxygen, and animals use oxygen and give off carbon-dioxide—how convenient!
please help , thank you !!
Which is the best description of a molecule?
A molecule of an element is composed of at least two types of atoms.
A molecule of a compound is composed of only one type of atom.
A molecule of a compound is composed of at least two types of atoms.
A molecule of an element is composed of exactly two types of atoms.
Answer:
I think its the first one but im not 100%
Explanation:
Answer:
its c :)
Explanation:
brainlist please
Can you post all the answers for "Mass and Atoms Quick Check" NO need explanation
Which statement describes the quantities that can be found using the number of moles?(1 point)
Question 1: Which statement describes the quantities that can be found using the number of moles?
Answer: It can be used to find the number of molecules, atoms, or ions.
Question 2: A scientist uses 3 g of water (H2O) in an experiment. Which option describes the first step in calculating the number of molecules in 3 g of water?
Answer: Identify the molar masses of H and O.
Question 3: The molar mass of ammonia (NH3) is 17.03 g/mol. Which expression correctly shows how to determine the number of moles of ammonia equivalent to 5 g?
Answer: 5 g×1 mol/17.03 g
Question 4: How many molecules of carbon dioxide (CO2) are there in 0.450 mol of carbon dioxide?
Answer: 2.71×1023
Question 5: When magnesium chloride (MgCl2) is dissolved in water, which statement must be true?
Answer: The sum of the mass of the Mg2+ ions and the mass of the Cl– ions must be equal to the mass of MgCl2.
HELP PLEASE I HAVE TO TURN THIS TEST IN 10 MINUTES
An evacuated cylinder has a volume of 50 liters. If 20 liters of nitrogen gas and 20 liters of oxygen gas are pumped into this evacuated cylinder, how much of the cylinder is filled with the two gases?
Only 80 percent because only 40 out of 50 liters are used.
The entire container because gases will expand to fill it.
Only 80 percent because of the low molecular weight of the two gases.
The entire container because of the low molecular weight of the two gases.
A standard solution of 112 ppm Yellow 6 dye was prepared. A 25.1 mL aliquot of the stock Yellow 6 dye was diluted to 25 mL in a volumetric flask. What is the concentration (in ppm) of this dilute Yellow 6 dye
Answer:
multiply, 112 and 25.1 then divide the answer in six
Explanation:
The concentration of of dilute yellow 6 dye is 112.448 ppm.
What is ppm solution?PPM or parts per million is a term in chemistry used to denote very low concentrations of solution.It is defined as milligrams of substance present in 1 liter of solution.
It is technically a dimensionless quantity useful for measuring smaller concentrations present in a solution.This conversion has many scientific applications .
It is how many parts a particular compound or molecule takes up within the one million part of the whole solution. It is used for describing concentrations of substances which are usually dissolved in a solvent.
For calculating ppm concentration when two solutions one with ppm concentration is known can be found out by:
ppm of solution-1 ×volume=ppm of solution-2×volume
112×251=ppm of solution-2×25
=112.44 ppm
For calculating ppm of solution both the parts of the equation must have same weight or volume.
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A gas tank contains 3 gases (N2, O2, and CO2). The total pressure of the gases is 825mmHg. If Pco2 = 125mmHg and Po2= 350mmHg, what is the partial pressure of N2 gas?
Answer:
350mmHg
Explanation:
Use Dalton law
Total=P gas 1+p gas 2+ P gas 3
825=P1+350+125
825=P1+475
825-475= P1
P1= 350 mm Hg
What does it mean when something on the internet “goes viral”? How is this similar to a virus spreading through a community?
Please help !!!!
Answer:
When something goes viral on the internet, it gets really popular. As it gets more and more popular, more people see it. For instance, as a video becomes viewed more and more, it is recommended to more and more people to watch.
This is a good example of how a virus spreads. As more and more people receive the virus in a community, more and more people get it. Then, the more likely it is to spread to more people.
Explanation:
I hope this helps. I didn't know if you wanted a 500 word essay or something...
Answer:
it's when you post something and everyone likes it that's what viral means
Select the correct answer from each drop-down menu. To prepare a 2 M solution of potassium nitrate (KNO3), which quantities must be measured? The mass of the and the volume of the must be measured.
Molarity determines the molar concentration of the solute dissolved in the solution. Mass and volume should be measured for the estimation of the molarity.
What is molarity?Molarity is the mass of the solute present in the litre of solution. It is also called molar concentration as it estimates the concentration of the compounds.
The unit of molarity is mol/L and can be given by the formula:
[tex]\rm Molarity(M) = \rm \dfrac{ \text{Mass of solute}}{\text{Molar mass of solute}}\times \text{Volume of Solution in L}[/tex]
Therefore, for the formation of a 2M potassium nitrate solution, the volume of the solution and mass of the solute is required.
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Bubbles started appearing in a pot of water kept on the stove. This shows the process of
(1 Point)
A. evaporation
B. condensation
O C. freezing
O C. boiling
C. boiling
when water starts boiling you will se bubbles appearing
The mass of an object is 240g and its volume is 60 cm3
will it sink or float
Answer:
Float
Explanation:
Becuase 240 g had more volume then the 60 cm3 which is lighter that the mass of 240 grams
Write the Noble Gas Notation for Silicone
Answer:
[Ne] 3s2 3p2
Explanation:
Neon (Ne) is the noble gas right before silicon (Si).
Then right after neon is the 3s subshell. It has two electrons and is full.
After 3s comes the 3p subshell, and silicon only has two electrons in the 3p subshell (you can just count the electrons in each subshell on your periodic table).
10 elements and what you know about their properties and reactions.
Answer:
Hydrogen. H.
Helium. He.
Lithium. Li.
Beryllium. Be.
Boron. B.
Carbon. C.
Nitrogen. N.
Oxygen. O.
Fluorine
Neon
Explanation:
The site of transcription initiation is the
promoter.
sigma factor.
start codon.
origin of replication.
!!!!CHEMISTRY HELP NEEDED 25 POINTS!!!!
Use the equation for Charles’s Law to calculate the following. (2pts)
A balloon is filled up to 1 liter at a temperature of 294.15K. The balloon is then placed in a freezer for 24 hours at a temperature of 273.15K.
What is the volume of the balloon when it is taken out?
Answer:
It had changed by .001 liters because of the way that cold air can't evaporate more than .5 liters of air
Explanation:
Cold Feet It is January and Sabrina, Kelly and Jill are tired of having cold feet while waiting for the school bus to come in the morning. They decide to design an experiment to test the effectiveness of wool, cotton and nylon as insulators. They fill identical bottles with 200 mL of water at 100oC and place inside each sock. They take the temperature of the water after 20 minutes. Identify the variables::: 1. Independent Variable: 2. Dependent Variable: 3. Identify two constants:
Answer:
Independent Variable : type of insulator material used
Dependent Variable: temperature of water
Constants: Type of bottle used, volume of water in each bottle
Explanation:
In discussing any experiment, the important factors are; the independent variable(s), dependent variable (s) and constant (s).
In this experiment, the type of insulator material (wool, cotton and nylon) was manipulated and the temperature of water when each insulator is used was carefully measured. The type of bottle and volume of water in each bottle were held constant
The nature of insulator material (independent variable) determined the temperature of the water (dependent variable) when the type of bottle and volume of water in each bottle were held constant.
By comparing the temperature of water when the different insulator materials were used, the best insulator material can be deduced.
When a rock is rolled along the bottom of the stream the rock will become
Answer:
smaller
Explanation:
hope this helps!
please help with this question
thx
Ava wants to use an inflatable rubber raft to do a polar bear plunge on New Year’s Day. She inflates the raft to one atmosphere in her garage at room temperature, 20°C. She then drives out to the lake where she and her friends are going to swim very briefly in water at a temperature of 1°C.
( A )the decrease in temp will cause a decrease in the volume of the raft nd this drop in volume of the raft and this drop in volume may cause Ava to sink while on raft.
( B ) The decrease in temp will cause an increase in the volume of the raft and this increase in volume may cause Ava to sink while on the raft.
( C ) the decrease in temp will cause a decrease in the volume will help keep Ava afloat
( D )the decrese in temp will cause an increase in the volume of the raft and this increase in volume of the raft and this increase in volume will keep ava afloat.
Answer:
A the decrease in temp will cause a decrease in the volume of the raft and this drop in volume of the raft and this drop in volume may cause Ava to sink while on raft.
The Sun keeps all of the planets orbiting it because _____.
A. he Law of Ellipses states that the planets orbit the Sun in circular patterns
b. the Law of Universal Gravitation states that an increase in mass causes an increase in gravitational force
C. the Law of Harmonies states that the motion of the planets will not stop unless an outside force is applied
D. the Law of Equal Areas states that planets sweep equal areas in equal periods of time around the Sun
Answer:
a. because of how the earth circulates around the sun.
BRAINLY I NEED PLS ASP! Its science I NEED HELP PLS
Answer:
B
Explanation:
Answer:
b or c
Explanation:
which ever one u think make more sense
b. inference meaning- a conclusion raeched on the basis of evidence and reasoning
c. scientific notation meaning-a way to express real numbers that are too large or too small to be conveniently written in decimal form.
Which of the following parts pumps the blood throughout the body?
[tex]\huge\bold\green{Answer:-}[/tex]
Both venae cavae (7) pass the deoxygenated blood to the right atrium. Blood from the right atrium (1) enters right ventricle (2) and pulmonary arteries (6) carry deoxygenated blood from right ventricle to lungs for oxygenation. Two pulmonary veins (8) come from each lung and pass oxygenated blood to left atrium (3). The left ventricle (4) pumps blood into the aorta (5) which in turn branches and delivers blood to the major body regions and organs.So, the correct answer is option A.
A bird flies 45 meters in 3 seconds. What is its speed?
What is the Largest water animal!
Answer:
Blue Whale
Explanation:
I hope this helps:)
Answer:
The blue whale!
Explanation:
6. What happens to the movement of molecules when their temperature is
raised?
Q: What happens to the movement of molecules when their temperature is
raised?
A: When heat is added to a substance, the molecules and atoms vibrate faster. Hope this helps!
Predict the fact is all great white sharks were removed from an aquatic ecosystems. Write a short radio ad explaining why sharks should be protected .
In a chromatography experiment, how do you identify the components of an unknown mixture?.
The components in an unknown mixture are separated based on differences in their speed along the stationary phase.
What is chromatography?Chromatography is a separation technique which us used to separate the components of a colored mixture based on the ability of the components to move along a medium at different speeds.
The components of a colored mixture have different densities and different adsorption properties.
Thus they move at different speeds over the stationary phase of the chromatogram.
Therefore, the components of an unknown mixture are separated based on differences in their velocity in the stationary phase.
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What volume will 2.0 moles of nitrogen occupy at 720 torr and 20.0°c? formula: pv = nrt (r = 62.396 l•torr/mol•k) 3.5 l 6.6 l 48 l 51 l
The ideal gas law is the state equation of a hypothetical ideal gas. The volume of the nitrogen gas is 51 I.
What is the ideal gas equation?The general gas equation, commonly known as the ideal gas law, is the state equation of a hypothetical ideal gas. The ideal gas equation is formulated as:
PV = nRT
In this equation, P refers to the pressure of the ideal gas, V is the volume of the ideal gas, n is the total amount of ideal gas that is measured in terms of moles, R is the universal gas constant, and T is the temperature.
As it is given that the pressure on the nitrogen is 720 torr, the temperature of the gas is 20°C(293 k), and the moles of nitrogen are 2.0 moles. Therefore, using the ideal gas equation the volume of the nitrogen can be written as,
[tex]pv=nRT\\\\v = \dfrac{nRT}{p}\\\\v = \dfrac{2 \times 62.396 \times 293}{720}\\\\v = 50.7834 \approx 51[/tex]
Thus, the volume of the nitrogen gas is 51 I.
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Answer:
answer in picture
Explanation:
What model would represent individual atoms of different types that repeat to form a crystal
Answer:
Although atoms are the smallest units that can be found in all matter, these atoms have a complex structure when experimentally analyzed. In order to understand almost all concepts in chemistry, it is essential to clearly understand the basic structure of an atom. Crystals are solid compounds made out of a number of atoms or molecules. There are particular arrangements in crystals. These arrangements are called crystal structures. Examining the crystal structure is very important in determine
Explanation:
Answer:
Although atoms are the smallest units that can be found in all matter, these atoms have a complex structure when experimentally analyzed. In order to understand almost all concepts in chemistry, it is essential to clearly understand the basic structure of an atom. Crystals are solid compounds made out of a number of atoms or molecules. There are particular arrangements in crystals. These arrangements are called crystal structures
Explanation:
Hua Tuo, with the character Yuanhua and his childhood name Yan, was a native of Qiao County, Peiguo (now Bozhou City, Anhui), and was an alchemist and physician in the late Eastern Han Dynasty.
Answer:Hua Tuo practiced medicine throughout his life and was proficient in internal medicine, surgery, gynecology, pediatrics, acupuncture and moxibustion. The characteristic is that only a few herbs are used, and only a few herbs are used; Acupuncture is only one or two needles. Before placing the needle, he said to the patient: "Take a certain Xu, if it comes, speak to someone" (the needle will reach a certain part, if you feel it, tell me). Sickness will be cured.
How many moles are in a mass of 800.0 g of magnesium?
Answer:
32.92 moles of Mg
Explanation:
To convert grams to moles (Or vice versa) of any chemical compound we need to use the molar mass of the substance (That is, how many grams weighs 1 mole of the chemical).
The magnesium, Mg, has a molar mass of 24.305g/mol. That means in 800.0g of Mg you have:
800.0g * (1mol / 24.305g) =
32.92 moles of MgDefine Magnetic force and Magnetic field
Answer:A magnetic field is a vector field that describes the magnetic influence on moving electric charges, electric currents, and magnetized materials. A charge that is moving in a magnetic field experiences a force perpendicular to its own velocity and to the magnetic field
Explanation:hope this helps :DD