Answer:
oxygen is needed for all cells to function
If an atom has 15 electrons, how many protons does the atom have?
A:16
B:15
C:14
D:this cannot be determined without looking at a periodic table first
Answer:
15
Explanation:
it would probably be the same number!
Answer:
Explanation:
15
state two things you notice when a metal is touched
Answer:
touched touched
Explanation:
rusting can occure
sonority may take place
The scattering of a stream of positively charged particles when striking a thin film of gold confirms that the positive charge in an atom must be located in a dense central mass. atoms contain electrons in varying energy layers around the nucleus. electrons are found in the center of an atom. electrons can only be found within predicted areas surrounding the nucleus.
Answer:
According to Thompson's model, Every atom consists of a positively charged sphere of radius 10-- 10m in which entire mass and positive charge of the atom are uniformly distributed inside the sphere electrons are embedded like seeds in watermelon. According Rutherford entire poistive charge and mass of the atom are concentrated in a tiny central core of the atom which is called atomic nucleus contains. Size of nucleus = 10-- 15m. The nucleus contains protons and neutrons. Negatively charged electrons revolve around the nucleus in circular orbits.
Explanation:
Answer:
A
Explanation:
A chemistry class is experimenting with iodine to see which common white powder items will react and make the iodine change color. Which item listed will have a chemical reaction with iodine?
Answer:
The question did not contain any listed options. However, starch is a common white powder that will give a color change on reacting with iodine molecules
Explanation:
Iodine is a common indicator used in the lab to detect the presence of starch or starchy substances.
Iodine molecules react with amylose in starch to form a complex with a deep blue-black coloration.
Hence, a common white powder which reacts with iodine molecules to give a blue-black color must be a substance that contains starch.
The answer is:
d) cornstarch
zinc does not give hydrogen on reaction with nitric acid
Answer:
The Hydrogen gas produced during its reaction with metal gets oxidised to H2O, hence no hydrogen gas is produced. Instead it evolves nitric oxides such as NO2,NO etc.
Indica que tipo de reacción es cada una, escribe el nombre que le corresponde a cada una. 1.Mg + H2SO4 → MgSO4 + H2 2. 2 KI + Pb(NO3)2 → PbI2 + 2 KNO3 3. 2 Zn + O2 → 2 ZnO 4. Zn + CuSO4 → ZnSO4 + Cu 5. Na2CrO4 + 2 AgNO3 → Ag2CrO4 + 2 NaNO3 6. H2O → 2 H2 + O2 7. SO3 + H2O → H2SO4 8. HCl + NaOH → NaCl + H2O 9. Cl2 + 2 KBr → 2 KCl + Br2 10. CaCO3 → CaO + CO2
Answer:
Ver respuesta abajo
Explanation:
En este caso, para saber el tipo de reacción de cada uno, necesitamos saber los tipos de reacción, que en este caso son los siguientes:
a) Combinación (C): Tan sencillo como que tengo 1 elemento o compuesto, que se combina con otro elemento o compuesto, formando uno nuevo:
A + B ----> AB
b) Desplazamiento (D): aquí un elemento reemplaza a otro en un compuesto, formando un compuesto nuevo:
A + BC ----> AC + B
c) Descomposición (Ds): Es lo opuesto a combinación. Un compuesto se descompone o se separa en dos o mas elementos básicos por efecto del calor o electricidad:
AB ----> A + B
d) Doble desplazamiento (DD): en este caso, dos elementos de compuestos diferentes se intercambian, formando nuevos compuestos:
AB + CD ------> AC + BD
Siguiendo estos pequeños conceptos, veamos el tipo de reacción de cada reacción puesta:
1. Mg + H2SO4 ----> MgSO4 + H2 (D) (Mg desplaza al H2)
2. 2KI + Pb(NO3)2 ----> PbI2 + 2KNO3 (DD) (K y Pb intercambian compuestos)
3. 2Zn + O2 ----> 2ZnO (C) (se unen el Zn y el O)
4. Zn + CuSO4 ---->ZnSO4 + Cu (D) (Zn reemplaza al Cu)
5. Na2CrO4 + 2AgNO3 ----> NaNO3 + Ag2CrO4 (DD) (Na y Ag forman dos compuestos nuevos)
6. 2H2O ----> 2H2 + O2 (Ds) (El agua se separa en dos elementos)
7. SO3 + H2O ----> H2SO4 (C) (se formó un nuevo compuesto)
8. HCl + NaOH ----> NaCl + H2O (DD) (Na y H formaron dos compuestos nuevos)
9. Cl2 + KBr ----> 2KCl + Br2 (D) (Cl reemplaza al Br)
10. CaCO3 ----> CaO + CO2 (Ds) (CaCO3 se separó en dos compuestos)
Dos vehículos colisionan. Se sabe que antes del choque el vehículo 1 de masa "m", se desplazaba horizontalmente hacia la derecha con U1=10 m/s y el vehículo 2 cuya masa es el 30 % de la masa del vehículo 1, se desplaza horizontalmente hacia la izquierda con velocidad de 8m/s. Si hay pérdida de energía en la colisión, la expresión matemática que mejor representa dicha situación es:
Answer:
translate? ill edit this later
Explanation:
13. Which statement best describes an element? *
O any combination of two or more atoms of different types
a pure substance made up of only one kind of atom
O
a substance containing only water molecules
O any kind of crystal
Explanation:
Distinguish chemical substances from mixtures
Key Points
Matter can be broken down into two categories: pure substances and mixtures. Pure substances are further broken down into elements and compounds. Mixtures are physically combined structures that can be separated into their original components.
A chemical substance is composed of one type of atom or molecule.
A mixture is composed of different types of atoms or molecules that are not chemically bonded.
A heterogeneous mixture is a mixture of two or more chemical substances where the various components can be visually distinguished.
A homogeneous mixture is a type of mixture in which the composition is uniform and every part of the solution has the same properties.
Various separation techniques exist in order to separate matter, including include distillation, filtration, evaporation and chromatography. Matter can be in the same phase or in two different phases for this separation to take place.
Terms
substanceA form of matter that has constant chemical composition and characteristic properties. It is composed of one type of atom or molecule.
elementA chemical substance that is made up of a particular kind of atom and cannot be broken down or transformed by a chemical reaction.
mixtureSomething that consists of diverse, non-bonded elements or molecules.
Answer:
a pure substance made up of only one kind
Explanation:
We can prove a theory to be correct by performing the right experiment. False or true
Answer:
true
Explanation:
because if you find the right answer that proves the theory to be correct.
what is the safety rule that keeps ocean from being poisoned?
Answer:
Death in the Water: How Plastic Is Poisoning Our Oceans
Liz Greene February 17, 2017
We live in a society obsessed with convenience, and that obsession has made plastic king. Though humankind has greatly benefited from plastic, the environmental costs of this reigning polymer may bring about our downfall. Traveling from land to sea in the wind or through waterways, plastic pollution is causing extensive damage to our marine life and giving life to one of the greatest ecological disasters of our times.
Plastic has been collecting in the marine environment since plastic production began in the 1950s — in fact, each square mile of the ocean contains more than 46,000 pieces of floating plastic. Eight million metric tons of plastics make their way into the ocean each year, hitching a ride on the currents and reaching the furthest corners of our seas — even turning up in the Antarctic wilderness. Simply put, the world’s oceans are becoming a toxic soup of plastic and other debris, and all life is being negatively affected.
Unfortunately, plastic doesn’t biodegrade — though it does eventually photodegrade (i.e., break down into smaller fragments by exposure to the sun). Photodegradation of plastic continues to the molecular level, yet photodegraded plastic remains a polymer. No matter how minute the pieces, they will always be plastic. Unlike naturally based paper or glass, they are not absorbed into or changed by natural processes — plastic never truly goes away.
Explanation:
This is a really good article I found, hope it helps
Provide two arguments on why you don't notice the land moving beneath you, defend your answer.
Answer:
The reference point is the ground.
Explanation:
•Moves slow that you don't notice hope this helps you :) god loves you :)
A cylinder rod formed from silicon is 21.3 cm long and has a mass of 5.00 kg. The density of silicon is 2.33 g/cm3. What is the diameter of the cylinder? (the volume of cylinder is given by π r2h, where r is the radius and h is the length)
Answer:
11.32cm
Explanation:
This question describes a cylinder rod formed from silicon with length 21.3cm and mass 5kg. The density of the silicon is 2.33g/cm3.
To calculate the diameter, the radius is needed. To calculate the radius, the volume is needed. To calculate the volume, the formula: density = mass (m) / volume (V) is used.
Mass = 5kg, which is 5 kg × 1000g = 5000g
Density= 2.33g/cm3
Hence; volume= mass / density
= 5000/2.33
= 2145.9 cm3
Volume of cylinder= πr^2h
Where h= 21.3cm and π= 3.142
That is; r^2 = volume/πh
= r^2 = 2145.9/3.142×21.3
= r^2 = 2145.9/66.9246
= r^2 = 32.06
r= √32.06
r= 5.66cm
If radius of the cylinder is 5.66cm, the diameter is twice of the radius.
That is, diameter (d) = 5.66 × 2
= 11.32 cm
Therefore, the diameter of the cylinder is 11.32cm.
Students in physics class are asked to find the relationship between the length of a pendulum (string with a weight at the bottom) and the time it takes for one pendulum swing. What is the dependent variable in this experiment?
Answer:
1)[tex]Time \ for \ pendulum \ swing \ left \ and \ right = 2 \times \pi \times \sqrt{\dfrac{Length \ of \ the \ pendulum \ string}{g} }[/tex]
2) The dependent variable = The time it takes for one pendulum swing
3) The independent variable = The length of the pendulum string with weight at the bottom
Explanation:
The relationship between the length of the pendulum string and the time it takes for one pendulum swing is giving as follows;
[tex]T = 2 \cdot \pi \cdot \sqrt{\dfrac{L}{g} }[/tex]
Where;
T = The period of oscillation = The time to complete one oscillation =Two swings of the pendulum
L = The length of the pendulum
g = The acceleration due to gravity
Therefore, the time it takes for one pendulum swing is directly proportional to the square root of the length of the pendulum
The dependent variable = The time it takes for one pendulum swing
Th independent variable = The length of the pendulum string with weight at the bottom.
An ion is neutral and has no charge. True or False
Answer:
Explanation:
False but I could be wrong but I’m pretty sure.
Answer:
False.
Explanation:
An ion has an imbalanced number of protons and electrons. Hope this helps! =)
What is the specific heat of a 75.01 g piece of an unknown metal that exhibits a 45.2°C temperature change upon absorbing 1870 J of heat?
Answer:
[tex]Cp=0.552\frac{J}{g\°C}[/tex]
Explanation:
Hello,
In this case, the formula to compute the required heat based on the mass, specific heat and change in temperature is widely known as:
[tex]Q=mCp\Delta T[/tex]
In such a way, since we are asked to compute the specific heat, we solve for it as shown below:
[tex]Cp=\frac{Q}{m\Delta T}=\frac{1870J}{75.01g*45.2\°C} \\ \\Cp=0.552\frac{J}{g\°C}[/tex]
Best regards.
The specific heat of the metal exhibiting 45.2 [tex]\rm ^\circ C[/tex] temperature change has been 0.55 J/g.[tex]\rm ^\circ C[/tex].
The specific heat can be defined as the amount of heat required to raise the temperature of 1 gram of a substance by 1 degree Celsius.
The expression can be given as:
Q = mc[tex]\Delta[/tex]T
where, Q = heat required = 1870 J
m = mass = 75.01 g
c = specific heat capacity
[tex]\Delta[/tex]T = change in temperature = 45.2 [tex]\rm ^\circ C[/tex]
1870 J = 75.01 g [tex]\times[/tex] c [tex]\times[/tex] 45.2 [tex]\rm ^\circ C[/tex]
c = [tex]\rm \dfrac{1870}{75.01\;\times\;45.2}[/tex]
c = 0.55 J/g.[tex]\rm ^\circ C[/tex]
The specific heat of the metal exhibiting 45.2 [tex]\rm ^\circ C[/tex] temperature change has been 0.55 J/g.[tex]\rm ^\circ C[/tex].
For more information about the specific heat capacity, refer to the link:
https://brainly.com/question/13369050
1. If my car gets 26 miles to the gallon and the tank can hold 13.2 gallons of gas, how many miles can I travel?
Answer:
343.2 miles
Explanation:
To find the miles that you can travel with 13.2 gallons of gas, you can use a rule of three given that you know that the car gets 26 miles to the gallon:
1 gallon → 26 miles
13.2 gallons → x
x=(13.2*26)/1
x= 343.2
According to this, the answer is that you can travel 343.2 miles.
What is the maximum amount of electrons that can be in the third energy level of an atom? (question continued in comments)
Answer:
18 electrons
Explanation:
If you search on Google you get the same answer, so the question gives you your answer.
Calculate the solubility of CaF2 in water at . You'll find data in the ALEKS Data tab. Round your answer to significant digits.
Answer:
[tex]0.016\frac{g}{L}[/tex]
Explanation:
Hello,
In this case, the dissociation of calcium fluoride is:
[tex]CaF_2(s)\rightleftharpoons Ca^{2+}(aq)+2F^-(aq)[/tex]
And the equilibrium expression is:
[tex]Ksp=[Ca^{2+}][F^-]^2[/tex]
Which is useful to compute the molar solubility, symbolized by [tex]x[/tex] as the reaction extent:
[tex]Ksp=(x)(2x)^2[/tex]
In such a way, since the solubility product of calcium fluoride at 25 °C is 3.45x10⁻¹¹, the molar solubility is found to be:
[tex]3.45x10^{-11}=(x)(2x)^2\\\\x=\sqrt[3]{\frac{3.45x10^{-11}}{4} }\\ \\x=2.05x10^{-4}M=2.05x10^{-4}\frac{molCaF_2}{L}[/tex]
And the solubility, considering its molar mass 78.08 g/mol is:
[tex]=2.05x10^{-4}\frac{molCaF_2}{L}*\frac{78.08gCaF_2}{L}\\ \\=0.016\frac{g}{L}[/tex]
Regards.
what is the moden periodic law
Answer:
Here's what I get
Explanation:
The modern periodic law states that the physical and chemical properties of the elements are periodic functions of their atomic numbers.
[tex] \LARGE{ \underline{ \purple{ \bf{Required \: answer:}}}}[/tex]
When everything wasn't discovered yet....The Scientists gave different opinions and ways to classify the elements discovered in their time.
Modern Periodic table was the most accepted model for arranging the elements on the basis of their Atomic number. So, we can also say that they are also dependent upon the electronic configurations of those elements. It was put forward by Moseley.
#KeepOnExploring
what are the four rules for significant figures
Answer:
Significant Figures
Explanation:
1) Annotation category: ...
2)RULES FOR SIGNIFICANT FIGURES.
3) All non-zero numbers ARE significant. ...
4)Zeros between two non-zero digits ARE significant. ...
5)Leading zeros are NOT significant. ...
6)Trailing zeros to the right of the decimal ARE significant. ...
7)Trailing zeros in a whole number with the decimal shown ARE significant. 8) to make you happy :) hope this helps you :)
This flow chart shows the amount of energy that is emitted by each type of light. ultraviolet > blue light > yellow light > red light (maximum energy) (minimum energy) In an experiment, shining which type of light on a strip of metal would be least likely to produce the photoelectric effect?
Answer: bright red light
Explanation:
im taking edge
If all cells are created by other living cells, which of the following is true?
O Spontaneous generation cannot occur
O Plant cells come from other plant cells
O Cells divide for
reproduction
O All of the answers are correct
cells divide for reproduction
Find the density of a substance that has a mass of 75 g and a volume of 35 mL. Don't forget your units!
Answer:
The density of a substance that has a mass of 75 g and a volume of 35 mL is 2.14 [tex]\frac{g}{mL}[/tex]
Explanation:
Density is a characteristic property of a substance that relates to the amount of mass it has per unit volume. In other words, density is the property that matter, whether solid, liquid or gas, has to compress into a given space (it measures the amount of mass in a given volume of a substance). It is calculated as the quotient between the mass of a body and the volume it occupies:
[tex]density=\frac{mass}{volume}[/tex]
In this case, you know:
mass= 75 gvolume= 35 mLReplacing:
[tex]density=\frac{75 g}{35 mL}[/tex]
Solving:
[tex]density=2.14\frac{g}{mL}[/tex]
The density of a substance that has a mass of 75 g and a volume of 35 mL is 2.14 [tex]\frac{g}{mL}[/tex]
The density should be2.14 g/ml.
Given that,
A mass of 75 g and a volume of 35 mL.Based on the above information, the calculation is as follows:
[tex]Density = mass \div volume\\\\ = 75 \div 35[/tex]
= 2.14 g/mL
Learn more: https://brainly.com/question/15959704?referrer=searchResults
what are fundamentals quantities ? Name them .
Answer:
Fundamental quantities or base quantities are:
✔️Lengthy
✔️Mass
✔️Time
✔️ Temperature
✔️Electric current
✔️Amount of substance
✔️Intensity of light
Explanation:
Hope it will help you :)
All of the following are true statements EXCEPT a. Solids have a definite volume and a definite shape. b. Liquids have less energy than solids. c. There are no intermolecular interactions between the particles of a gas. d. Sublimation occurs when a solid phases into a gas.
Answer:
The correct answer is B. Liquids have less energy than solids. This is false because liquids have more energy than solids; the particles in a liquid are moving whereas the particles in a solid are almost still (they may vibrate slightly). This increase in speed of particles translates to kinetic energy, showing us that liquids have more energy than solids.
Explanation:
We can also examine the other answer choices and show why they are incorrect.
Solids have a definite volume and shape. Think about solids in your house; for example, think about a chair or a block. The shape of these items cannot be changed, and their volume is unchanging.
There are no intermolecular forces between the particles of a gas. This is assumed to be a property of an ideal gas, which makes sense since the particles in a gas are farther from each other than those in a liquid or a solid.'
Sublimation occurs when a solid turns into a gas. This is also a true statement; when a solid sublimes, it changes into a gas without ever becoming a liquid.
Hope this helps!
10) What are the four main spheres of planet?
Answer:
the four main spheres of the earth are geosphere, hydrosphere, atmosphere and biosphere
Explanation:
geosphere consists of all rocks on Earth
atmosphere which are the gases that surrounds the earth
hydrosphere which is all the water on the earth
biosphere which are the living things on the earth
At STP what is the volume of 2.56 mol CH4?
Answer:
Volume = 57.34 dm³Explanation:
The volume of a gas can be found by using the formula
V = n × V(dm³)
where
n is the number of miles
V is the volume
V(dm³) is the volume of 1 mole of a gas at STP which is 22.4 dm³
From the question
n = 2.56
The volume is
V = 2.56 × 22.4
We have the final answer as
Volume = 57.34 dm³Hope this helps you
If your mixing cement for the foundation of a building and it calls for 1.55 tons of sand, how many grams of a sand are you using? Please show your work, and report your answer with the correct number of significant figures and appropriate units.
Answer:
1406136 grams
Explanation:
What is the meaning of electrolysis?
Answer:
A process in which a chemical change, especially decomposition, is brought about by passing an electric current through a solution of electrolytes so that the electrolyte's ions move toward the negative and positive electrodes and react with them.
Answer:
a pgsysyyssysyysysyshshshshshshshshshshshshshss
On a cold morning, the smoke coming out of a chimney is observed to be in blue color. What could be the reason? Name the effect and the reason for the effect
Stack effect? I'm not totally sure about this...
Explanation:
Large amount of tiny particles of water droplets, dust and smoke are present on a misty day. These tiny particles in the air scatter blue colour of white light passing through it. When this scattered light reaches our eyes, the smoke appears blue.