Answer:
B. False is the rite answer
A certain element has a half-life of three years.
If you currently have a 10g sample of that element and you know that it has undergone five half-life decays, how many grams of the element were in the sample originally?
A
150g
B
160g
C
320g
D
50g
(C) 320 g
Explanation:
A = A02^(-t/hl)
where hl = half-life
A0 = original amount
A = present amount
t = elapsed time = 5 half-lives
10g = A02^(-5) = A0/32
A0 = 32×(10 g) = 320 g
A substance has a boiling point of 78 °C. Which of the following is true about the substance? (5 points) a It will also change from a gas to a solid at 78 °C while the gas loses energy. b It will also change from a gas to a solid at 78 °C while the gas gains energy. c It will also change from a gas to a liquid at 78 °C while the gas loses energy. d It will also change from a gas to a liquid at 78 °C while the gas gains energy.
Answer: If a substance has a boiling point of [tex]78^{o}C[/tex] then it is true that it will also change from a gas to a liquid at 78 °C while the gas loses energy.
Explanation:
The temperature at which vapor pressure of a liquid substance becomes equal to the atmospheric pressure is called boiling point of substance.
At the boiling point, liquid phase and vapor phase remains in equilibrium.
This means that as liquid phase changes into vapor phase and also vapor phase changes into liquid phase at the boiling point.
Thus, we can conclude that if a substance has a boiling point of [tex]78^{o}C[/tex] then it is true that it will also change from a gas to a liquid at 78 °C while the gas loses energy.
I can't do Miscellaneous calculations!
E.g.
How many moles of oxygen atoms are present in 2.5 mole of water molecules?
Describe one way in which advances in space technology have improved our understanding of objects in space.
Answer:
Technology helps us in many ways.
Explanation:
We can now research the world even more effectively and at a higher level of sophistication thanks to technological advancements. Telescopes, on the other hand, enable us to peer into the far corners of the universe and detect very large objects such as stars. Electron microscope enable us to see smaller objects such as cells and organisms.
Write out a “for every” statement that relates the amount of methane to the amount of oxygen gas (CH4 + 2O2 = CO2 + 2H2O)
Answer:
For every one molecule of methane, one molecule of oxygen is required to release one molecule of CO2 and 2 molecule of H2O
Explanation:
As we can in the balanced equation below -
CH4 + 2O2 = CO2 + 2H2O
One molecule of CH4 reacts with two molecule of oxygen to release one molecule of CO2 and 2 molecule of H2O.
Hence, it can be said
For every one molecule of methane, one molecule of oxygen is required to release one molecule of CO2 and 2 molecule of H2O
why do different people have differently shaped proteins?
The sequence of amino acids in the chain determines how the chain will fold up to make the protein, so different proteins have different three-dimensional shapes. ... This is because proteins form attachments and interact with many other molecules and structures inside organisms.
What are the 3 most valuable metals in the United States? A. Lead b. Gold c. Iron d.Copper e.Coal f.Silver g.Titanium
Answer:
Gold, Silver and Titanium
Explanation:
The most valuable metals in the list are:
Gold:
Its value makes it a good investment option. Gold can be used in many different ways, like in jewelry, electronics, medicine, etc.
Silver:
Similar to the case of gold, besides the common value of silver in jewelry, it can be also used in other ways, because it has a large thermal and electrical conductivity.
Finally, the titanium: It's price is actually close to the copper one, but for the cost of work with titanium (Titanium has a really large melting point, then melting it into ingots needs a lot of energy), the price of titanium is increased.
during prophase a group of fibers called what forms the cell
Answer:
During prophase, the nucleus disappears, spindle fibers form, and DNA condenses into chromosomes ( sister chromatids ). During metaphase, the sister chromatids align along the equator of the cell by attaching their centromeres to the spindle fibers.
Explanation:
Convert 4.1x10^-4 moles of carbon into atoms.
Answer:
2.5×10^20atoms
Explanation:
number of moles= number of particles/Avogadro's constant
number of particles=Avogadro's constant × number of moles
number of particles=(6.02×10^23) × (4.1×10^-4)
number of particles=2.5×10^20
what does molecule mean?
a.) A pure substance, only one type of atom
b.) Two or more atoms held together by chemical bonds
c.)Composed of two or more separate elements
d.)The smallest part of matter still retaining chemical properties
A pure substance, only one type of atom
Answer:
(a) a pure substance, only one type of atom
PLESE HELP WILL GIVE BRAINLYESTY
Imagine that you are Sir Isaac Newton. Write a short autobiographical statement that talks about who you are, where you’re from, and some of your important contributions.
Answer:
My name is Isaac Newton and I am a scientist. I am known as one of the most important scientists in history. I was born in Woolsthorpe, England on January 4, 1643. My father, a farmer who was also named Isaac Newton, had died three months before my birth. My mother remarried when I was three years old and left me in the care of my grandparents.
Explanation:
WILL GIVE BRAINLIEST!!
What adaptation helps the pelican to swim?
Big wings
Long beak
Strong legs
Webbed feet
if 300.0g of chlorine is reacted how much calcium hydroxide is needed to react with it
Answer:
334.7g of Calcium Hydroxide are needed
Explanation:
Based on the reaction:
2Ca(OH)2 + 2Cl2 → Ca(ClO)2 + CaCl2 + 2H2O
2 moles of chlorine react with 2 moles of calcium hydroxide.
To solve this question we must find the moles of chlorine in 300.0g. These moles = Moles of Ca(OH)2. With the moles of calcium hydroxide we can find its mass as follows:
Moles Cl₂ (Molar mass: 70.90g/mol)
300.0g Cl₂ * (1mol / 70.90g) = 4.2313 moles Cl₂ = Moles Ca(OH)₂
Mass Ca(OH)₂ (Molar mass: 74.093g/mol)
4.2313 moles Ca(OH)₂ * (74.093g / mol) =
334.7g of Calcium Hydroxide are needed1) Draw a particle picture of liquid lemonade turning into a solid popsicle
BEFORE
AFTER
Explanation:
The particles are further apart in liquids than in solids so when the lemonade changes from a liquid to a solid, the particles would become closer.
Can u guys help me I have an f in science and this will help me a lot with my grade.
Answer:
First slide:
1) diffusion
2)water
3)high
4)low
5)balance
Second slide:
1)movement
2)without
3)energy
4)high
5)low
6)equilibrium
Final slide:
1)passive
2)energy
3)randomly
4)high
5)low
6)equilibruim
7)permeable
8)Osmosis
9)water
Hopes this helps! Good luck!
Explain what happens when there is a lot of extra greenhouse gases in our atmosphere. Explain what happens when there's not enough greenhouse gases in our atmosphere. Based on those answers, are greenhouse gases inherently good or bad? Explain.
Explanation:
Here is why: If the atmosphere contains too much of these gases, the whole Earth becomes a hotter and hotter greenhouse. The atmosphere holds onto too much of the heat at night instead of letting it escape into space. Then, the next day, the Sun heats Earth's surface even more.
is zinc an example of a element or compound?
Answer:
Zinc is an element.
Explanation:
Compounds are composed of two or more elements
Answer:
element
Explanation:
zinc is an element with atomic number 30
What is the main factor that controls the type of volcano that forms
following eruption?
Answer:
the buoyancy of the magma, the pressure from the exsolved gases in the magma and the injection of a new batch of magma into an already filled magma chamber
The buoyancy of the magma is the main factor that controls the type of volcano that forms following eruption.
What is volcano?A volcano is a crack in the crust of the Earth, another planet, or a satellite from which molten rock, hot stone pieces, and hot gases are released in eruptions. An amazing demonstration of Earth's might is a volcanic eruption.
Eruptions may cause catastrophic loss of lives and property, particularly in areas of the planet that are highly inhabited, despite the fact that they are beautiful to observe. The buoyancy of the magma is the main factor that controls the type of volcano that forms following eruption.
Therefore, the buoyancy of the magma is the main factor that controls the type of volcano that forms following eruption.
To know more about volcano, here:
https://brainly.com/question/14400711
#SPJ6
5. A sample of an unknown metal has a mass of 120.4 g. As the sample cools from 90.5°C to 25.7°C, it releases 7020. J of energy. What is the specific heat of the sample? Identify the metal among those in the data table below. Finally, is this endothermic or exothermic?
Answer: The specific heat capacity of the sample is [tex]0.899 J/g^{o}C[/tex] and as heat is released in this reaction so it is exothermic in nature.
Explanation:
Given: Mass = 120.4 g
Heat energy released = -7020 J
Initial temperature = [tex]90.5^{o}C[/tex]
Final temperature = [tex]25.7^{o}C[/tex]
Formula used is as follows.
[tex]q = m \times C \times (T_{2} - T_{1})[/tex]
where,
q = heat energy
m = mass of substance
C = specific heat capacity
[tex]T_{1}[/tex] = initial temperature
[tex]T_{2}[/tex] = final temperature
Substitute the values into above formula as follows.
[tex]q = m \times C \times (T_{2} - T_{1})\\-7020 J = 120.4 g \times C \times (90.5 - 25.7)^{o}C\\C = \frac{-7020 J}{120.4 \times (-64.8^{o}C)}\\= \frac{7020 J}{7801.92} J/g^{o}C\\= 0.899 J/g^{o}C[/tex]
When heat is released in a process or reaction then it means it is exothermic in nature.
Thus, we can conclude that the specific heat capacity of the sample is [tex]0.899 J/g^{o}C[/tex] and as heat is released in this reaction so it is exothermic in nature.
If you have 2.9 x 10^21 atoms of nitrogen, how many moles do you have?
Answer: Approximately [tex]0.48 \times 10^{-2} \ \text{ mole}[/tex]
============================================================
Explanation:
There are roughly 6.02 * 10^23 atoms in one mole of any element. So we have 6.02 * 10^23 atoms in one mole of nitrogen.
We can then do the following conversion:
[tex]\left(2.9 \times 10^{21} \ \text{ atoms of nitrogen} \right)\times \left(\frac{1 \ \text{ mole}}{6.02 \times 10^{23} \ \text{ atoms}}\right)\\\\\frac{2.9 \times 10^{21}}{6.02 \times 10^{23}} \ \text{ mole}\\\\\frac{2.9}{6.02} \times 10^{21-23} \ \text{ mole}\\\\0.48172757 \times 10^{-2} \ \text{ mole}\\\\0.48 \times 10^{-2} \ \text{ mole}\\\\[/tex]
How does competition among different species lead to extinction?
[tex]\huge{\textbf{\textsf{{\color{pink}{An}}{\red{sw}}{\orange{er}} {\color{yellow}{:}}}}}[/tex]
Interspecific competition often leads to extinction. The species that is less well adapted may get fewer of the resources that both species need. As a result, members of that species are less likely to survive, and the species may go extinct.
Thanks Hope it helps.Which of these elements will successfully create a 1:1 bond with Carbon (C)
Carbon (C)
Silicon (Si)
Beryllium (Be)
Oxygen (0)
Answer:
Option B, Silicon
Explanation:
The valency of Carbon is 4 as it has four electrons in its outermost shell
The valency of Si is also four hence C
Hence Silicon can form 1:1 bond with the carbon
Valency of Beryllium is 2, hence it can not form 1:1 bond with carbon. Similarly the valency of oxygen and carbon are way different to form 1:1 bond
hence, only option B is correct
3. a. How many moles of NaCl are dissolved in 152 mL of a solution if the concentration of the solution is 0.364 M?
Answer:
Good luck man
Explanation:
Good luck man
What is the molality of a solution in which 0.32 moles aluminum chloride has been dissolved in 2,200 g water
Why are infants and children often more susceptible to the effects of toxic substances than adult? (Explain)
From what I know personally from learning about this type of subject in the past is that children are more susceptible to the effects of toxic substances more than adults are, certain scientific data specifically indicate that children actually are for all intents and purposes more basically susceptible to toxic exposure than adults because they for the most part have proportionally definitely more intake of food contaminants, basically active developmental processes, basically multiple exposure pathways and really susceptible kind of socio-behavioral activities in a particularly major way.
A student uses visible spectrophotometry to determine the concentration of CoCl2(aq) in a sample solution. First the student prepares a set of CoCl2(aq) solutions of known concentration. Then the student uses a spectrophotometer to determine the absorbance of each of the standard solutions at a wavelength of 510nm and constructs a standard curve. Finally, the student determines the absorbance of the sample of unknown concentration. The original solution used to make the solutions for the standard curve was prepared by dissolving 2.60g of CoCl2 (molar mass 130.g/mol) in enough water to make 100.mL of solution. What is the molar concentration of the solution
Answer:
0.200 M
Explanation:
Step 1: Given data
Mass of CoCl₂ (m): 2.60 gMolar mass of CoCl₂ (M): 130. g/molVolume of solution (V): 100. mL (0.100 L)Step 2: Calculate the moles (n) of CoCl₂ (solute)
We will use the following expression.
n = m / M
n = 2.60 g / (130. g/mol) = 0.0200 mol
Step 3: Calculate the molar concentration of the solution
Molarity is equal to the moles of solute divided by the liters of solution.
M = n/V
M = 0.0200 mol/0.100 L = 0.200 M
2.3g of lithium chloride in 500cm3 of solution
Answer:
0.109M
Explanation:
Find molarity of the solution:
Molarity is defined as the ratio between the moles of the solute (Lithium Chloride in this case) per liter of solution. To solve this question we have to find the moles of LiCl and its volume as follows:
Moles LiCl -Molar mass: 42.394g/mol-
2.3g * (1mol / 42.394g) = 0.0543 moles
Volume in liters:
500cm³ * (1L / 1000cm³) = 0.500L
Molarity:
0.0543 moles / 0.500L =
0.109M
A man needs to lift a heavy box on the back of a truck or push up a ramp or lift it straight up from the ground to use around he won't have to move the box over a longer distance what did is the benefit of using a ramp to get the box
To objects (A and B) of the same temperature are in contact with each other? Which statement is true.
A. Heat transfers from object A to object B, because molecules from a collide with those from B.
B. No heat transfers because there are no collisions between the molecules of the objects
C. Heat transfers from object B to object A, because molecules from B collide with those from A
D. Although the molecules collide, no heat transfers because there is no temperature difference between the objects
In order to tell the difference between microwaves and visible light in the blue range, which of the following measurements should be made?
Answer:
microwaves should be made
Answer:
answer choices plzzzzz
ima edit my answer wht are the choices
Explanation:
mrk mE BRAINLIEST PLZZZZZZZZZZZz