Answer:
water vapour is there
Explanation:
thats all i know
Michelle learns in science class that simple machines such as an inclined plane can change the amount of force needed to lift heavy objects. She decides to test this with an experiment.
Michelle chooses a 10 kg weight. She sets up a ramp made of smooth metal that makes an angle θ with the floor. She attaches a spring scale to the weight and the top of the ramp in order to hold the weight in place. She records the force from the spring scale, then changes θ and records it again. She repeats this several times.
In this experiment, what is the dependent variable?
A.
the mass of the weight
B.
the angle θ between the ramp and the ground
C.
the amount of force on the spring scale
D.
the material the ramp is made of
Be fast please
A student decided to research primate psychology for their science project. They measured how long it took gorillas to adapt to their new habitat when moved from one zoo to another. They measured how long it took the new gorilla to interact regularly (more than 3 times per day) with the gorillas that already live there. Seven different cases were examined and the data collected. What can be said about the data? [GorillaTime to interact (days)12.523.138.343.352.763.273.4]
[
Gorilla 1 2 3 4 5 6 7 Time to interact (days) 2.5 3.1 8.3 3.3 2.7 3.2 3.4
]
A. The data is only measured to one decimal place, so it is not reliable.
B. The data falls within similar ranges so it may be reliable.
C. The data is reliable because there is only one outlier.
D. The data may not be reliable because there is an outlier.
Answer: the answer is D im pretty sure
Explanation:
Kinetic molecular theory states... (choose all that apply)
A. There is a chemical change when a solid melts to a liquid.
B. Particles that make up matter have kinetic energy.
C. Particles that make up matter are always in motion
What is force and motion
Answer:
In physics, a force is any interaction that, when unopposed, will change the motion of an object. A force can cause an object with mass to change its velocity (which includes beginning moving from a state of rest), i.e., to accelerate. Force can also be described intuitively as a push or a pull.
lol
True/False: Units for gas density are grams/L
Answer:
false
Explanation:
How many atoms are in this formula? 2Fe
Answer:
two
Explanation:
There are two atoms in 2 Fe, more correctly written as 2Fe or Fe2. Both atoms are from the same element, iron.
Answer:
2
Explanation:
There are two atoms of the same element in 2Fe.
Hope this helps! :)
a molecule for sulfur dioxide consists of one sulfur atoms (S) and two oxygen atoms (0). what is the chemical formula for this compound
Electrons will pair up in an orbital only when
Answer:
All orbitals in the same sub level have one electron
Explanation:
All orbitals in the same sub level have one electron
A sample contain 33.42g of metal pellets are poured on to a graduated cylinder initially containing 12.7ml of water, causing the water level to rise to 21.6ml. Calculate the density of the metal
Answer:
3. 76 g/ml^3
Explanation:
We are given the mass of the metal pellets which is 33.4 grams. To calculate the density of the metal, we need to divide the mass by the volume. The volume of the metal is not directly given so we need to find it ourselves. The water was initially 12.7 ml and then it rose to 21.6 ml after placing the metal pellets. This indicate that the volume of the metal pellets is 8.9 ml.
[tex]21.6 - 12.7 = 8.9[/tex]
We can now use the density formula.
[tex]p = \frac{m}{v} [/tex]
[tex]p = \frac{33.42}{8.9} [/tex]
[tex]p = 3.76[/tex]
The density of the metal is equal to 3.76 g/ml.
What is the density?The density of an object can be defined as the mass per unit volume. The average density is equal to the total mass of the object divided by the total volume of the object.
The mathematical formula for the density of the material is expressed as follows:
Density = Mass/Volume
The S.I. unit of the density is Kg/m³ and is an intrinsic property as it is independent of the size. If the size increases, the mass increases as well but the density of the material remains constant.
Given the mass of the metal, m = 33.42 g
Volume of the metal = Volume of water level with metal - volume of water
V = 21.6 -12.7 = 8.9 ml
The density of metal = 33.42/8.9 = 3.76 g/ml
Therefore, the density of the metal is 3.76 g/ml
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Un estudiante preparo 200 ml de solución de acetato de potasio (CH3COOH ; Masa molar = 98 g/mol ; Ka CH3COOH = 1,8 x 10-5), disolviendo 3,5 g de ácido, la que denomino "Solución A". Posteriormente preparo otra solución de menor concentración del mismo soluto que denomino "solución B" y para ello tomo un volumen de 5,5 ml de la solución A y agrego agua hasta 70 ml de solución. Señale el pH de solución A y B y, la concentración molar de CH3COO- en la solución b.
Answer:
mirar respuesta abajo
Explanation:
Muy bien. Antes de responder lo que piden en el problema, vamos a calcular la concentración inicial de la solución A:
1) Concentración de la solución A:
En este caso, se sabe que se usaron 3,5 g de la sal, se puede calcular los moles usando el peso molecular y la masa:
n = m/PM (1)
Aplicando tenemos:
n = 3,5 / 98 = 0,0357 moles
Conociendo los moles, podemos calcular la concentración:
M = n/V (2)
Aplicando la formula tenemos:
M = 0.0357 / 0.200 = 0.1785 M
Esta es la concentración del ácido etiquetado como "Solución A".
Ahora podemos ver la concentración de la solución B, para luego calcular las concentraciones molares de los iones en solución y sus respectivos pH.
2) Concentración del ácido en la solución B:
Con la concentración de "A", se puede determinar la concentración de la solución B. Aqui podemos esperar que sea un valor mas bajo, puesto que es una dilución la que estamos haciendo. Por lo tanto.
Si se toma 5.5 mL de la solución A, entonces:
n = 0.1785 * 0.0055 = 0.00098 moles
Con esto, se calcula la nueva concentración:
M = 0.00098 / 0.070 = 0.014 M
Esta es la concentración de la solución B. Ahora para calcular pH y concentraciones de los iones en equilibrio, hay que plantear la reacción acido base en equilibrio. Como es el mismo compuesto, usaremos la misma ecuación.
3) pH de las soluciones A y B:
Planteamos la reacción de equilibrio:
CH₃COO⁻ + H₂O <------> CH₃COOH + OH⁻ Kb
Calculando el Kb, sería asi:
Kb = Kw/Ka
Kb = 1x10⁻¹⁴ / 1.8x10⁻⁵ = 5.56x10⁻¹⁰
Ahora reescribimos la ecuación y hacemos una tabla de equilibrio:
CH₃COO⁻ + H₂O <------> CH₃COOH + OH⁻ Kb = 5.56x10⁻¹⁰
i) 0.1785 x x
eq) 0.1785-x x x
Kb = [OH⁻] [CH₃COOH] / [CH₃COO⁻]
Reemplazando nos queda:
5.56 * 10⁻¹⁰ = x² / (0.1785-x)
Y como Kb es muy pequeño, se asume que el valor de x será también pequeño, asi que podemos redondear la resta a simplemente 0.1785, quedando tan solo:
5.56 * 10⁻¹⁰ = x² / (0.1785)
x² = 5.56*10⁻¹⁰ * 0.1785
x = √9.9246*10⁻¹¹
x = 9.96*10⁻⁶ M
Esta es la concentración de [OH⁻] y [CH₃COO⁻] en la solución A.
Aplicando lo mismo para la solución B (Cambiando solo el dato de concentración) nos queda:
x = √5.56*10⁻¹⁰ * 0.014
x = 2.79x10⁻⁶ M = [OH⁻] = [CH₃COO⁻]Finalmente, para calcular pH, se calcula primero el pOH y luego el pH:
pH = 14 - pOH
pOH = -log[OH⁻]
Para la solución A:
pOH = -log(9.96*10⁻⁶) = 5
pH = 14 - 5
pH = 9En el caso de la solución B:
pOH = -log(2.79*10⁻⁶) = 5.55
pH = 14 - 5.55
pH = 8.45Espero te ayude
Mark is in charge of making change at his family's garage sale on a hot summer day. He runs low on change and brings out a jar of pennies from the house. He keeps the lid off of the jar. Later in the day, he notices that the pennies are hot. Which statement best explains what happened?\
Answer:
This question is incomplete
Explanation:
The question is incomplete without the options. However, when a metal (in this case what the pennies are made of) is left in direct contact with the heat from the sun, it conducts this heat and becomes hot. This process is called thermal conduction. The thermal energy is readily accepted by the material in which the pennies are made of thereby increasing the thermal energy of the penny coin which then makes the pennies hot after being left under the sun.
What is the process whereby scientists check each other’s work?
A. defining the audience
B. conferencing
C. peer reviewing
D. writing
Answer:
peer reviewing
Explanation:
Its peer reviewing because there peers and there reviewing eachothers work
The process whereby scientists check each other’s work is peer reviewing.
What is peer group?Peer group are the groups of people of same age, same background with same interest.
In the peer reviewing process group of members will check, evaluate and correct each others work, which in turn help the members of the group to update their work.
Hence, option (c) is correct i.e. peer reviewing is the process whereby scientists check each other’s work.
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Name the gas evolved when Zn reacts with dil.HCI (choose the answer from the following)
1. O2 2. H2 3. CO2 4. Cl2
Answer:
H₂
Explanation:
Help it’s for a test!!!!!!!!!!!How many moles are in 2.16 x 1023 atoms of magnesium?
A. 35.9 moles
B. .359 moles
C. 7.18 moles
D. 0.359 moles
E. 0.90 moles
Which of the following is an example of very early scientific research?
sleeping in caves to avoid predation by animals
painting pictures and symbols on cave walls
making baskets from reeds
banging rocks together to see which make a spark and create fire
Answer:
banging rocks together to see which make make a spark and create fire painting pictures is an example of art and sleeping in caves is survival
1.) Electromagnetic waves that you can see are called:
A) Ultraviolet rays
B) microwaves
C) visible light
D) infrared rays
2.) These waves have the longest wavelength and the lowest frequency.
A) infrared waves
B) radio waves
C) microwaves
D) gamma rays
3.) Which wave has high enough energy to cause damage to skin and sometimes cancer?
A) Ultraviolet rays
B) microwaves
C) visible light
D) infrared rays
4.) Waves with high frequency have a ___________ wavelength
5.)Electromagnetic waves are _________ waves, the energy of the wave moves at right angles to the direction of travel.
6.) Which type of wave travels faster in a vacuum: visible light or radio waves? Explain your answer.
7.) What Electromagnetic wave has the highest frequency? What does that mean about the energy of this type of wave?
8.) Mechanical waves like sound require a medium to travel. Are electromagnetic waves mechanical waves? Why or Why not?
9.) Identify each type of electromagnetic wave from the illustration.
(The photo comes with this question)
True or False: A Precipitate is a solid
that forms out of a liquid solution as a
result of a chemical reaction
Answer:
true because it undergoes a tranformation
Explanation:
A mixture cannot be reversed back to it’s original properties (true or false)
Answer:
False
Explanation:
A mixture is composed of two or more substances that are combined through physical means. It has NOT undergo any changes in its chemical properties. So, even though its appearance change, it can be reverted back.
Answer:
That answer would be false.
Explanation:
Depending on the type of mixture, you can separate it and reverse it back to its original properties through filtration, evaporation, distillation, and chromatography.
What is the ratio of aluminum atoms to oxygen atoms in aluminum oxide?
Answer:
Al2 O3 or 2:3
Explanation:
The aluminum oxide consists of two elements, which are oxygen atoms and aluminum atoms, and there are 2 aluminum atoms and 3 oxygen atoms in aluminum oxide. The ratio from aluminum atoms to oxygen atoms is 2:3.
There are two types of chemical compound one is covalent compound and other is ionic compound, covalent compound formed by sharing of electron and ionic compound formed by complete transfer of electron. Therefore, the ratio of aluminum atoms to oxygen atoms in aluminum oxide is 2:3.
What is chemical Compound?Chemical Compound is a combination of molecule, Molecule forms by combination of element and element forms by combination of atoms in fixed proportion.
An ionic compound is a metal and nonmetal combined compound. Ionic compound are very hard. They have high melting and boiling point because of strong ion bond. The ratio of aluminum atoms to oxygen atoms in aluminum oxide is 2:3. Aluminium oxide is an ionic compound.
Therefore, the ratio of aluminum atoms to oxygen atoms in aluminum oxide is 2:3.
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3.58 x 1023 molecules of propane C8H8 would occupy how much space at STP
Answer: At STP, a mole of gas takes up 22.4 Liters. The 22.4 Liters/mole quantity can be derived from the Ideal Gas Law, PV = nRT, plugging in STP conditions for P and T, and solving for V/n, which gets 22.4 Liters/mole.
Explanation:
The missing components in the table to the right
are indicated with orange letters. Complete the
table by filling in the corresponding number(s) or
symbol(s) below.
A
B
1111
С
D
E
F
G
The Atomic Number (Z) indicates the number of protons in an atom of an element. If the atom is neutral then the number of protons will be equal to the number of electrons. So the atomic number can also indicate the number of electrons.
Mass Number (A) = Number of protons + Number of Neutrons
Atomic Number (Z) = Mass Number (A) - Number of Neutrons
Atomic number = number of protons = number of electrons ⇒ neutral atoms
Atomic number - positive charge = number of electrons ⇒ cation
Atomic number + negative charge = number of electrons ⇒ anion
You can also see the periodic system
A. Indium (In)
B. proton = electron = 27
C. proton = electron = 73
D. proton = electron = 49
E=F. atomic mass - neutron = 137 - 81 = 56
G. atomic mass-proton = 115- 49 = 66
H. 181-73 = 108
Answer:
I know I´m kinda late but....
Explanation:
A. In
B. 27
C. 73
D. 49
E. 56
F. 54
G. 66
H. 108
I. 32
Would love some help pleaseee. and please at least read the question instead of skipping it please.
Measuring tools can have errors. Errors lead to ___________________ results and _______________ conclusions. To calculate the difference of the accepted value and the experimental value, scientists use this formula:
percent error = (experimental value − ) × 100. accepted value
Minimizing Bias
People show bias when they want everyone to accept their results. Bias can arise for many reasons:
• Companies show bias when they depict only the research details that are in the best interest of their ____________.
• Scientists may be biased toward their _____________ and modify results suit their needs.
• Scientists may also show to bias get their research published in ______________ ______________.
Such biases often lead to _______________ facts. An important part of scientific thinking is identifying biases and taking the necessary steps to minimize them.
For results to be considered scientifically accurate, any scientist, regardless of his or her own bias, should be able to replicate the experiment and get the same results.
Summary
Think of some studies you’ve heard about. How can you tell whether the studies were well-designed and scientifically accurate or had biases?
Answer: this looks like your homework
Explanation:if you want help you are going to have to ask a specific question instead of giving people your homework.
Answer:
Honestly I would search this up maybe there might be a pdf with the answers. Sorry chemistry isn't my thing:(
Explanation:
.Over a period of 1,000 years, a lake becomes a maple forest. Is this process primary or secondary succession? Explain your answer.
Answer:
It is secondary succession.
Explanation:
primary succession only occurs in areas where there was no previous ecosystem
In the production of maple forest over the 1,000 years period, there has been the presence of the lake. Thus the production in the lake has been the secondary succession.
The primary and secondary succession has been the development process in the ecosystem. The ecosystem development can be taken place when there has been no previous vegetation, or when there has been the available ecosystem.
The primary succession can result when there has been no available previous ecosystem. The secondary succession can take place when there has been a previously existing ecosystem.
In the production of maple forest over the 1,000 years period, there has been the presence of the lake. Thus the production in the lake has been the secondary succession.
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Which of the following elements are characterized by having full outermost s and p
orbitals?
F. Period 7
G.
Group 8A
H.
Inner transition elements
J.
Periods 4, 5, and 6
Answer:
Group 8A
Explanation:
Group 8A elements are characterized by having full outermost s and p orbitals. These elements are also known as the noble gases or inert gases. They occupy the last group on the periodic table.
They are known to have an outer shell configuration of ns² np⁶The configuration reveals that atoms of all the elements have completely filled orbitals in their outer shell sublevels. This accounts for the non-reactivity of elements in this group. Most of the elements in the group have high ionization energy and very low electron affinity values.Some of the elements in this group are Neon, Argon, Krypton, Xenon, and Radon.
What is Arsenic cost per unit?
Answer:
arsenic costs $320 per 100g
Explanation:
The bright red line from the emission spectrum of hydrogen has a wavelength of 657 nm. What is the energy, in joules, of a single photon of this light? 4.35 x 10–40 J 3.03 x 10–28 J 3.03 x 10–19 J 4.56 x 1014 J
Answer:
3.03 × 10^-19 J
Explanation:
The energy, E, of a photon of light can be calculated by using the formula:
E = hv
Where; E is energy in Joules,
h is Planck's constant {6.626×10^−34J}
v is frequency of light
For this question, the wavelength (λ) is given, not the frequency (v).
Hence, we use;
v= c/λ
Where v= frequency, c= speed of light (3×10^8m/s), λ= wavelength (657nm)
657nm = 657 × 10^-9m
v = 3×10^8/657 × 10^-9
v = 3/657 × 10^(8--9)
v = 0.00456 × 10^17
v = 4.56 × 10^14
Since frequency (v) = 4.56 × 10^14;
E = hv
E = 6.626×10^−34 × 4.56 × 10^14
E = 30.21 × 10^(-34+14)
E = 30.21 × 10^-20
E = 3.021 × 10^-19
Therefore, the energy of the photon of light is 3.02 × 10^-19 J
What explains the structure of metals and delocalized electrons?
A. the unit cell model
B. the geometric shape model
C. the covalent bond model
D. the electron sea model
stages of mitosis in order
Answer:
nucleus formed
prophase
metaphase
anaphase
telophase and cytokinesis
Which statement best explains why the air pressure is greater at the poles than at the equator
Answer:
At the equator, the altitude is lower, and also because of the direct heating of sun rays on the surface, the temperature is much higher than at the poles. This makes the air near the surface hot and lighter and hence it rises up which results in lower air pressure.
Explanation:
Plz give me brainliest .-.
The Greek philosopher Empedocles proposed the idea that
ALL matter was made of_____
elements.
Answer:
the four elements fire, air, water earth
Explanation: