Answer:
24
Explanation:
Because atomic number is the number of protons.
which statement best explains why chlorine is added to drinking water? A. Chlorine cures infections caused by bacteria or other microorganisms B. Chlorine protects people teeth against cavities C. Chlorine prepares the body to fight future infections D. Chlorine kills most pathogens in water
Answer:
to protect peoples teeth against cavities
Explanation:
i just know
Answer: its D
Explanation: A.P.E.X.
Which of these levels of ecological organization includes the other three?
A. community
B.ecosystem
C.organism
D.population
Which of the following compounds
does not contain a polar Covalent bond
A) CH2 CH₂ CH₂OH
B) ozone
C)CH₂ CH (NH₂) CH₂ CH2
D) CH4 CH₂ CH₂ Ch
H2 li
Answer:
the correct answer is letter B
The melting point of oxygen is -218°C and its boiling point is -183°C. What is the state of oxygen at -200°C?Immersive Reader
it is in a liquid state
Explanation:
A student investigated temperature changes during a reaction. Figure 2 shows the apparatus the student usesWhat is the biggest error in this investigation.Suggest two improvements to the apparatus which would increase the accuracy of the experiment.
[3 marks]
Answer:
it is becuse the students used wrong apparatus
The biggest error in this investigation is the use of inappropriate types of equipment.
The types of equipment used in the given setup are inappropriate. Suggested improvements in the apparatus to increase the accuracy are given below:
1. The use of a polystyrene cup in the laboratory for any reaction is inappropriate. As a slight increase in temperature causes the decomposition of the chemicals in the cup as well.
2. The use of a thermometer stand is a must. Without using the stand, the tip of the thermometer touches the lid of the container, which causes inaccuracies in the result.
Hence, all the suggestions are listed above.
Learn more about changes in temperature here:
https://brainly.com/question/31081480
#SPJ2
Karla is reading about a type of single-celled microorganism that can live inside the human body. This type of organism can either be harmful or harmless to people, depending on the type. One harmless type lives in the intestines and helps the body digest food. One harmful type can cause strep throat. Which type of organism is Karla most likely reading about?
A bacteria
B fungi
C parasites
D viruses
please help
Answer:
its bacteria
Explanation:
Single-celled organisms can directly take in nutrients from their outside ... Figure 1. The digestive systems of representative animals. Images from ... There are two types of animal body plans as well as two locations fordigestion to occur
Answer:
A bacteria
Explanation:
i did it LOL
The desert climate or arid climate, is a climate which there is an excess of evaporation over precipitation. During the days, the temperatures are very high and dry. During nightfall, temperatures drop dramatically and it gets very cold. In three to four sentences, describe one plant and one animal that you would expect to find in the arid biome. Support your answer with the abiotic factors in the biome. *
These desert dwelling, nocturnal creatures are very tough and low maintenance. Scorpions' exoskeletons and venomous stingers give them great protection, and their low food and water needs and ability to slow down their metabolism allow them to survive in the harshest environments.
what is the equation for hydrogen peroxide
Answer:
H2O2
Explanation:
2 hydrogen, 2 oxygen wikipedia it
Answer:
hey!
Your answer is that the equation for Hydrogen Peroxide is [tex]H_{2}[/tex][tex]O_{2}[/tex]
Explanation:
Its formed when [tex]H_{2}[/tex]O and [tex]O_{2}[/tex] react chemically together!
HOPE THIS HELPED!
Determine the number of moles in a 100.0g sample of water.
Answer:
5.55 moles is the answer ....
Explanation:
if 18g H2O is equal to 1 mole then 100 g H2O is how much?
100/18 which is 5.55
Answer:
5.551
Explanation:
100.0g x 1mol H20/18.015g H20 = 5.551 moles of H20
The 18.015g is from the periodic table. H = 1.008x2 = 2.016g H2
0= 15.999
15.999 + 2.016= 18.015
10. Johnny pushed a wheel borrow that was 50kg, if the net force on the
wheel borrow is 15N east, what is the wheel borrows acceleration?
What is the freezing point of a solution of 498mL of water (solute) dissolved in 2.50 L of ethanol (solvent), C2H5OH? The density of C2H5OH is 0.789g/cm3. (Remember that water has a density of 1.0 g/cm3.)
Answer:
Freezing T° of solution is -142.4°C
Explanation:
This excersise is about colligative properties, in this case freezing point depression,
ΔT = Kf . m . i
Where ΔT = Freezing T° of solvent - Freezing T° of solution
Kf = Cryoscopic constant
m = mol/kg (molality)
i = Number of ions dissolved.
Water is not ionic, so i = 1
Let's find out m.
We determine mass of water, by density
498ml . 1 g/mL = 498 g
We convert the mass of water to moles → 498 g . 1mol/18g = 27.6 moles
We determine mass of solvent by density
2500 mL . 0.789 g/mL = 1972.5 g
Notice, we had to convert L to mL to cancel units.
1 cm³ = 1 mL
We convert the mass from g to kg → 1972.5 g . 1kg /1000g = 1.97kg
We determine m = mol/kg → 27.6mol / 1.97kg = 13.9 m
Kf for ethanol is: 1.99 °C/m
Freezing T° for ethanol is: -114.6°C
We replace at formula: - 114.6°C - Freezing T° solution = 1.99 °C/m . 13.9 m . 1
- 114.6°C - Freezing T° solution = 27.8 °C
- Freezing T° solution = 27.8°C + 114.6°C
Freezing T° Solution = - 142.4 °C
Someone help me please!!!
A. 6 moles
B. 9 moles
C. 3 moles
D. 20 moles
I think please check me, in case I am wrong
The density of water H20 is bout 1 g/ml. If u have a bottled water that is 500 ml how many grams is this
Answer:
500 grams
Explanation:
500 milliliters x 1 gram per millileter = 500 grams.
discuss two physical and two chemical properties of Nitrogen
Answer:
Nitrogen gas (chemical symbol N) is generally inert, nonmetallic, colorless, odorless and tasteless. Its atomic number is 7, and it has an atomic weight of 14.0067. Nitrogen has a density of 1.251 grams/liter at 0 C and a specific gravity of 0.96737, making it slightly lighter than air.
Explanation:
Think about a synthetic material that you use every day. How
could that material be improved to better fit its function?
explanation: Synthetic fiber or synthetic fibre (in British English; see spelling differences) are fibers made by humans through chemical synthesis, as opposed to natural fibers that are directly derived from living organisms. They are the result of extensive research by scientists to improve upon naturally occurring animal and plant fibers. In general, synthetic fibers are created by extruding fiber-forming materials through spinnerets, forming a fiber. These are called synthetic or artificial fibers. Synthetic fibers are created by a process known as polymerization, which involves combining monomers to make a long chain or polymer. The word polymer comes from a Greek prefix "poly" which means "many" and suffix "mer" which means "single units". (Note: each single unit of a polymer is called a monomer). There are two types of polymerization: linear polymerization and cross-linked polymerization.
After the shuttle disaster, an unknown compound residue was removed from a piece of the debris. Upon analysis, it was found to contain 2.61 g of carbon, 6.09 g of nitrogen, and 1.31 g of hydrogen. What is its empirical formula?
Answer:
The final empirical formula is [tex]C_2 N_5 H[/tex]
Explanation:
Given
The amount of carbon, nitrogen and hydrogen in a given compound is as follows
C:N:H
[tex]2.61 : 6.09 : 1.31[/tex]
On simplifying the ration values we get
[tex]\frac{2.61}{1.31} : \frac{6.09}{1.31} : \frac{1.31}{1.31}[/tex]
So the final ratio is
[tex]2 : 5 : 1[/tex]
The final empirical formula is [tex]C_2 N_5 H[/tex]
What is the average atomic mass of the isotopes shown in the table?
Isotope Abundance (%) Mass of Isotope (amu)
Isotope-A
54.0
17.984
Isotope-B
32.0
18.985
Isotope-C
14.0
19.982
Answer:
18.58
Explanation:
From the question given above, the following data were:
Isotope A:
Abundance of A = 54%
Mass of A = 17.984 amu
Isotope B:
Abundance of B = 32%
Mass of B = 18.985 amu
Isotope C:
Abundance of C = 14%
Mass of C = 19.982 amu
Average atomic mass =?
AVERAGE = [(Mass of A × A%)/100)] + [(Mass of B × B%)/100] + [(Mass of C × C%)/100]
AVERAGE = [(17.984 × 54%)/100] + [(18.985 × 32%)/100] + [(19.982 × 14%)/100]
= 9.71136 + 6.0752 + 2.79748
= 18.58
Therefore, the average atomic mass of the isotope is 18.58 amu
Microscope Structure and Function Worksheet
Pdf
Pls match the letters according to the numbers
Pls answer for 25points
Pls do them correctly
HELPP PLEASEEEEEEEEEEEEE
Answer:
Potential energy I believe
Explanation:
how many atoms are in each compound ?
In eukaryotic cells, RNA is transcribed from DNA in the _____
ribosomes
nuclear membrane
cytosol
nucleus
Answer:
The answer is Nucleolus
Which of the following is NOT an atom that hydrogen bonds?
Select one:
a. Oxygen
b. Nitrogen
c. Fluorine
d. Sodium
Answer:
The answer is D sodium
Explanation:
Which of the following statements is true? According to the Law of Inertia, the Earth will stay in motion because it is already moving. The sun's gravitational pull keeps the Earth from moving in a straight line. The speed of the Earth's motion keeps it from crashing into the sun. All of the above.
Answer:
The Earth will stay in motion because it is already moving.
Answer:
b
Explanation:
A quanta of electromagnetic energy is called *
Answer: A quantum of electromagnetic energy is called a photon. Also, do you mean a quantum because I don't think a quanta is a thing
Explanation:
Step 9: Measure Pressure and Volume with the Book and 4 kg of Weight Total the mass on the syringe. Record it in the correct row of the data table. kg
Answer:
498 g
0.498 kg
Explanation:
Answer:
4.498 kg
1.47
35.0
51.5
Explanation:
1. compare a mixture and a compound , how are they like?
Answer:
Compound are substances which can be formed by chemically combining two or more elements. Mixtures are substances that are formed by physically mixing two or more substances.
I hope it's helpful!
Answer:
COMPOUND= A compound is a substance that is formed when two or more elements combine chemically .
MIXTURES= Mixtures consist of two or more substances simply mixed together , but not chemically combined .
Which additional claim can be BEST supported by the evidence from the skulls in the whale fossil record?
A.
The fossil record shows differences in the skulls of the mammals, which shows that they are from three separate species that all lived at the same time.
B.
The fossil record shows similarities in the skulls of the mammals, which shows that they must have had similar habitats and environments.
C.
The fossil record shows that some mammals evolved so that their nostrils are further at the top of their skull for better breathing while in the water.
D.
The fossil record does not give enough evidence about the mammals to determine if there is a relationship between the three skulls.
Answer:
d
Explanation:
Answer:
B
Explanation:
I think it is B because it starts out with it's nostrils so it is on the mouth causing it not to be able to breathe but over time it's nostril moved to the top of the head so they could breather better
Which of the following ideas is NOT accepted as true according to today’s atomic theory?
a. Atoms are the basic unit of matter
b. Electrons move in circular
paths around the nucleus
c. Protons, electrons, and neutrons are smaller than the atom
d.The nucleus has charged and uncharged particles
Answer:
D
Explanation:
hey guys i dont want to beg for help but i just am stuck in this q please help
I try this before but for me is letter C
Answer:
C
Explanation:
i took the test
45 grams of ammonia, NH3, in 0.75 L of solution.
