Answer:
I think As is larger
Explanation:
radium 226 has a half life of 1600 yers. suppose we have a 300g sample. how much remains after 200 years
Answer:
[tex]A=275.1g[/tex]
Explanation:
Hello.
In this case, since the radioactive decay is computed via:
[tex]A=A_0*2^{-\frac{t}{t_{1/2}}[/tex]
For the initial amount of Ra-226 (300 g), once 200 years have passed, the remaining mass is:
[tex]A=300g*2^{-\frac{200years}{1600years}}\\\\A=275.1g[/tex]
This is, considering that the half-life is 1600 years, it means that the mass of Ra-226 is decreased.
Best regards.
Subscripts are used in a chemical formula to show the number of atoms of each element.
True or False.
If endothermic means that the temperature increases and exothermic means it decreases, it 64 degrees to 64 degrees (it stayed the same) endothermic or exothermic?
Answer:
The answer is none of them.
Explanation:
I did the study guide...Also, if it has no change, it is neither.
What is the precise volume of the liquid
Imagine there is technology that allows scientists to see all of the movement of molecules inside living things. A scientist points this machine at the stem of a vascular plant and sees glucose molecules being transported to various parts of the plant. The scientist is looking at the movement of molecules through
the xylem.
the phloem.
the roots.
the cuticle.
Answer: C
Explanation: I looked it up lol
Which of the following substances will dissolve in water? Check all that apply.
Magnesium Sulfate
Methane
Butane
Sodium nitrate
Answer:
The answers are A. and D.
According to the concept of solubility and properties of ionic compounds, magnesium sulfate and sodium nitrate dissolve in water.
What is solubility?Solubility is defined as the ability of a substance which is basically solute to form a solution with another substance. There is an extent to which a substance is soluble in a particular solvent. This is generally measured as the concentration of a solute present in a saturated solution.
The solubility mainly depends on the composition of solute and solvent ,its pH and presence of other dissolved substance. It is also dependent on temperature and pressure which is maintained.Concept of solubility is not valid for chemical reactions which are irreversible. The dependency of solubility on various factors is due to interactions between the particles, molecule or ions.
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Identify the placement of items A-E using the drop-down menus.
A)
⇒No
⇒Yes
B)
⇒No
⇒Yes, when liquid or solution
⇒Yes, when solid
C)
⇒No
⇒Yes
D)
⇒No
⇒Yes
E)
⇒No
⇒Yes
Answer:
A=no
B= yes when liquid or solution
C=yes
D=no
E=yes
Explanation:
According to the given table, the placement of items A-E are
A) ⇒ No
B) ⇒Yes, when liquid or solution
C) ⇒Yes
D) ⇒No
E) ⇒Yes
What is conductivity and Malleability?
Malleability - Those metals that can be beaten into thin sheets with a hammer or any heavy object. For example - Cu, Au etc
Conductivity - Conductivity is the measure of the ease at which an electric charge or heat can pass through a material. For example - Metals are good conductors of heat and electrolytic solution is conductors of electricity.
Therefore, according to the given table, the placement of items A-E are
A) ⇒ No
B) ⇒Yes, when liquid or solution
C) ⇒Yes
D) ⇒No
E) ⇒Yes
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Describe the function of a cilia.
Answer:
hope it helps..
Explanation:
'Motile' (or moving) cilia are found in the lungs, respiratory tract and middle ear. ... These cilia have a rhythmic waving or beating motion. They work, for instance, to keep the airways clear of mucus and dirt, allowing us to breathe easily and without irritation.
Answer: to keep airway clear of mucus and dirt allowing us to breathe easy
Explanation:
Which organism on the geologic time scale are now extict
Answer:The Ordovician and Cambrian Periods are referred to as the "age of invertebrates", with trilobites abundant. In this period, brachiopods became more abundant that the trilobites, but all but one species of them are extinct today.
Explanation:
A dog has a mass of 19 kg. What is the mass of the dog in grams,expressed in scientific notation
Answer: 1.9 x 10^4
Explanation:
A dog has a mass of 19 kg. The mass of the dog in grams, expressed in scientific notation, is 1.95 × 10⁴ g.
What is mass?Mass is the quantity of matter in a physical body. The product of the compound's molar mass and the substance's moles are defined as mass.
Measuring units to determine the size, weight, or quantity of any object. Seven fundamental measurement units are utilized in daily life and across the globe.
These units of measurement are the meter, which is used to measure distance, and the second, which is used to measure. Grams and kilograms are the measuring units that are used to measure the quantity of a solid item.
The mass of the dog in grams is:
1 kilogram = 1000 grams
19.5 kg × (10³ g/1 kg) = 1.95 × 10⁴ g.
Thus, the mass of the dog in grams is 1.95 × 10⁴ g.
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Where is the north pole of the bar magnet, based on the magnetic field lines
shown?
Answer:On the Right End
Explanation: Trust me I just got it wrong on APEX to answer it for y’all On the right end is the correct answer
Answer:
Right end
Explanation:
Just did the quiz
When an atom is trying to obtain stability, what part(s) of the atom change(s)?
i need help please help me now please
Which of the following is a process that changes the composition of rocks from one material to another? (3 points) a Erosion b Deposition c Physical weathering d Chemical weathering
Answer:
ERosion i think
Explanation:
Answer:
Deposition
Explanation:
I hope you have a nice day(:
which statement describes how technology has increased our information on Mars?
A. The Curiosity rover found sulfur compound in rocks.
B.The Curiosity rover located methane in soil samples.
C. The Curiosity rover detected carbon in organic molecules.
D. The Curiosity rover discovered helium in underground pockets.
Answer:
Either D or C. I'm so sorry if I got you the wrong answer
Answer:
c
Explanation:
All of the following changes to a metal are physical changes except_____.
bending
melting
rusting
polishing
Answer:
D)Polishing..
Answer:
Wouldn't it be rusting
Explanation:
Melting and bending are physical changes so is polishing. so rusting is the only choice, for metal to rust wouldn't it need a chemical change.
Which is not a compound?
a. carbon dioxide gas
b. oxygen gas
c. silicone dioxide
d. water
Answer:
The answer is b oxygen gas b/c its an element
Explanation:
What is another name for radioactive dating?
Answer:
radioisotope dating is another name
Answer:
Radiometric dating
Explanation:
hope that helps
A new element was discovered. It’s average atomic mass was found to be 245.6 amu. Isotope #1 has a mass of 243.2 amu; isotope #2 has a mass of 244.9 amu; isotope #3 has a mass of 247.2 amu. Which isotope is most likely to be the most abundant?
A
Isotope 1
B
Isotope 2
C
Isotope 3
D
They all contribute the same amount
Answer:
B. Isotope 2
Explanation:
Isotopes can be defined as the atom of an element that has the same number of protons but different number of neutrons. This ultimately implies that, the isotopes of an element have the same atomic number (number of protons) but different atomic mass (number of nucleons).
Basically, the atomic mass of any chemical element found in the periodic table is equal to the weighted average of all its isotopes. Therefore, the isotope with the closest mass to the weighted average would be the most abundant.
In this scenario, a new element was discovered with an average atomic mass of 245.6 amu.
Isotope #1 has a mass of 243.2 amu.Isotope #2 has a mass of 244.9 amu.Isotope #3 has a mass of 247.2 amu.Hence, the isotope which is most likely to be the most abundant is isotope #2 that has a mass of 244.9 amu because it is closest in mass to the relative atomic mass (weighted average) of 245.6 amu.
The combination of two or more atoms, from the same or different elements, creates a(n).
a. element
c. molecule
b. atom
d. mixture
Please select the best answer from the choices provided
Pls help!!!! Fast!!!
B
С
D
Answer:
c Molecule
Explanation:
cuz science
What was the average speed of the truck for this trip?
Answer:
31.67 mph
Explanation:
To calculate the average speed of the truck, we must first obtain the total distance travelled by the truck followed by the total time taken for the truck to cover the distance travelled.
The following data were obtained from the question include:
Total distance) = 30 + 45 + 50 + 65 = 190 miles
Total time = 1 + 2 +1 +2 = 6 hours
Average speed =.?
Average speed = Total distance / Total time
Average speed = 190 /6
Average speed = 31.67 mph
Therefore, the average speed of the truck is 31.67 mph
Which of the following contribute(s) to most of the mass of an atom?
Question 6 options:
A)
Neutrons only
B)
Protons and neutrons
C)
Protons and electrons
D)
Protons only
Question 7 (5 points)
In a certain chemical reaction, the bonds of the products contain more energy than the bonds of the reactants. For the reaction to occur, which of the following best describes what occurred?
Question 7 options:
A)
Energy was released, so the reaction is endothermic.
B)
Energy was released, so the reaction is exothermic.
C)
Energy was added, so the reaction is endothermic.
D)
Energy was added, so the reaction is exothermic
Question 8 (5 points)
A solution
Question 8 options:
A)
is a single-phase homogeneous mixture.
B)
must contain water.
C)
is always a liquid.
D)
can contain more than two phases.
Question 9 (5 points)
Which of the following is true of alloys?
Question 9 options:
A)
They can only be composed of metals.
B)
They must be held together by chemical bonds.
C)
They're liquid solutions.
D)
They must contain a metal.
Question 10 (5 points)
Which of the following best describes an atomic number? An element's identity is defined by its atomic number; this means it represents the number of
Question 10 options:
A)
electrons in the element.
B)
neutrons in its nucleus.
C)
protons plus neutrons in its nucleus.
D)
protons in its nucleus.
Answer:
1.
B) protons and newtrons
2.
D)
3.
C)
4.
A)
How much MmHg are in 30.0 psi
Answer:
1551.45 MmHg
hope this helps :D
Which of the following compounds is the MOST polar?
H−Br
H−F
H−Cl
H−I
30 POINTS
Why would a scientist revise a model? (choose the best answer)
Group of answer choices
to cover up evidence from a previous experiment
to show off to other scientists
to add unnecessary details to the model
in order to better explain what is happening during a phenomenon
When modeling it is important to (pick two)
Group of answer choices
show beginning, middle and end if it fits the phenomenon
only use one color
make sure there is only drawings and nothing written
use zoom in bubbles to show the unobservable
Which of the following is NOT a limitation of a model
Group of answer choices
inaccurate colors
the type of material used to create the model
a messy model
shapes that are an approximation
Answer:
First Question: in order to better explain what is happening during a phenomenon
Second Question: show beginning, middle and end if it fits the phenomenon; use zoom in bubbles to show the unobservable
Third Question: the type of material used to create the model
Explanation:
First Question: You would not revise a model to "cover up evidence," that's scientifically immoral and should not be done, and showing off to other scientists is not the point of revising something.
Second Question: You should use more than one color to differentiate different parts of the model, but don't overwhelm it with color. There should be some labels in the model, so some writing is necessary.
Third Question: Inaccurate color representation does not technically limit a model unless color scheme is important, so this could be an answer, but not likely. A messy model limits a model because it makes it hard to read. Approximating shapes is a limitation because it portrays an incorrect representation of what system the model is of. The type of material used to create the model is most likely the right answer.
A element is having atomic number 82. find the number of its protons and electrons
Answer:
The number of its protons and electrons are 82 each
Explanation:
Atomic no of an element = 82
Atomic no = No of protons
⇒ No of protons = 82
Electrons are negatively charged particle and Protons are positively charged particles.
No of electrons = 82
Hence, the element is Lead with 82 protons and electrons
What can you infer is causing the cryosphere to change?
Answer:
Explanation:
The cryosphere—the portion of the Earth's surface where water is in solid form for at least one month of the year—has been shrinking in response to climate warming. ... The important outcome, however, is the change and the response the human social system (infrastructure, food, water, recreation) will have to that change.
The cryosphere the portion of the Earth's surface where water is in solid form for at least one month of the year has been shrinking in response to climate warming.
What is cryosphere ?The cryosphere includes all of the earth's frozen water, including glaciers and sea ice.
The lithosphere is the solid part of the earth made up of rocks, minerals, and other elements except the ocean. It is the part which present in the outer part of the earth which includes the brittle upper portion of the mantle and crust. The part of planet where living things can be found from the upper part of the atmosphere to the lower of the oceans and pools that are thermal and made up of the parts of earth where life present in all ecosystem is known as biosphere.
The atmosphere is the thin layer of gases that covers the outer part of the planet. It gives us the many different climates, or broad way of weather conditions around the world. The hydrosphere includes all of the water on earth from the oceans to glaciers and underground water and it can be liquid, vapour, or ice.
Therefore, the cryosphere the portion of the Earth's surface where water is in solid form for at least one month of the year has been shrinking in response to climate warming.
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5) A pure substance which can be decomposed by a chemical change is a
A) mixture
B) compound
C) metal
D) nonmetal
In chemistry lab, a student measured the density of liquid ethanol is 0.789 g/mL. Represent its density in units of 1b /in3? (2.54 cm = 1 in., 2.205 lb = 1 kg)
A. 9.09 x 10+ 1b / in
B.4.42 x 10-1b / in?
OC.2.85 x 10-2 16 / in
D. 0.106 16 / in?
O E.5.86 x 10" 16/in3
Answer:
Option C is correct option = 2.85×10⁻² lb/in³
Explanation:
Given data:
Density in g/mL = 0.789
Density in lb/in³ = ?
Solution:
It is given that,
2.54 cm = 1 in
2.205 lb = 1 kg thus,
1 mL = 1 cm³
0.789 g/cm³ × 1 kg/ 1000 g × 2.205 lb/1 kg × (2.54 cm / 1in)³
2.85×10⁻² lb/in³
The density of liquid ethanol is 0.789 g/mL, which is equivalent to 0.0285 lb/in³.
A student measured the density of liquid ethanol to be 0.789 g/mL and we want to convert it to lb/in³. We will need a series of conversion factors.
What is a conversion factor?A conversion factor is an arithmetical multiplier for converting a quantity expressed in one set of units into an equivalent expressed in another.
Step 1: Convert 0.789 g/mL to lb/mLWe will use the following conversion factors:
1 kg = 1000 g.1 kg = 2.205 lb.0.789 g/mL × (1 kg/1000 g) × (2.205 lb/1 kg) = 1.74 × 10⁻³ lb/mL
Step 2: Convert 1.74 × 10⁻³ lb/mL to lb/in³We will use the following conversion factors:
1 mL = 1 cm³.1 in = 2.54 cm.1.74 × 10⁻³ lb/mL × (1 mL/1 cm³) × (2.54 cm/1 in)³ = 0.0285 lb/in³
The density of liquid ethanol is 0.789 g/mL, which is equivalent to 0.0285 lb/in³.
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what is the name of CH3CH2CH2C(O)CH2CH3
Answer:
1-methoxypropane
Explanation:
Calculate the density of an
object with a mass of 20 g
and a volume of 2.3 mL.
Answer:
8.7g/mL
Explanation:
I used the density formula to solve. d=m/v= 20g/2.3mL
Answer:
8.7 g/ml
Explanation:
the formula for density is D = M/V