Answer:
1/8
Explanation:
Use logic,
every one hour, half of a radioactive remains
for the first hour, half remains
for the second hour, half of half remains or quarter remains
for the third hour, 1/2 of 1/2 of 1/2 or 1/8 remains
or use this equation
[tex]n = r ({ \frac{1}{2} })^{ \frac{f}{t} } [/tex]
where
n = amount after f time
r = amount of the original isotope
f = time
t = half-life
The law of conservation of momentum states that if objects exert forces only on each other, their total momentum is ____________. Group of answer choices
Answer:
Conserved.
Explanation:
Momentum can be defined as the multiplication (product) of the mass possessed by an object and its velocity. Momentum is considered to be a vector quantity because it has both magnitude and direction.
Mathematically, momentum is given by the formula;
[tex] Momentum = Mass * Velocity [/tex]
The law of conservation of momentum states that the total linear momentum of any closed system would always remain constant with respect to time.
This ultimately implies that, the law of conservation of momentum states that if objects exert forces only on each other, their total momentum is conserved.
What is a disadvantage of geothermal energy
Answer:
it runs the risk of triggering earthquakes. releases harmful gases
In _____ , materials move from an area of higher concentration to an area of lower concentration through a cell membrane.
1.selective permeability
2.active transport
3.passive transport
The four planets closest to the sun that are mostly made of rock and metal
Answer:
Mercury, Venus, Earth and Mars.
Explanation:
Density is defined by the equation d = m/v. Calculate the density of the wooden block, the rock, and the water by dividing the mass of each object by its volume.
Answer:
Density, d = 8.92 g/mL
Explanation:
Let mass of the wooden block, m = 46.83 g
The volume of the object, V = 5.25 mL
We need to find the density of the wooden block. The density of an object is given by its mass per unit volume.
density = mass/volume
[tex]d=\dfrac{46.83\ g}{5.25\ mL}\\\\=8.92\ g/mL[/tex]
So, the density of the wooden block is 8.92 g/mL.
Answer:
0.495 g/cm3
Explanation:
If I have ten eggs and lots of milk, flour and oil, how many
crepes can I make?
Answer:
I'd say about 8?
Explanation:
if you wanna make them huge make about 6
Which kind of energy change occurs when a candle is burning
Answer:
2 Answers. This would be chemical energy that is converted to heat. The heat from the wick melts the wax which gets absorbed in the wick and then gets burnt (which is really oxidation) to produce heat energy as well as light energy.
Explanation:
A candle must undergo a chemical reaction in order to burn, producing heat and light. As a result, energy changes from chemical energy to heat and light energy. As a result, as a candle burns, chemical energy is transformed into heat and light energy.
What is chemical energy ?Chemical energy is the energy that is released when chemical substances engage in a chemical reaction and change into other substances. Batteries, food, and gasoline energy are some instances of chemical energy storage media.
A type of potential energy associated with the structural organization of atoms or molecules is known as chemical potential energy. Chemical connections or interactions between molecules may have led to this configuration.
They are broken down into simpler molecules, such as glucose and amino acids, which are then either reassembled and stored in various forms, such as glycogen, or consumed as energy. Chemical energy in food is essential for giving our bodies the fuel they require to keep us alive and active.
Thus, energy changes from chemical energy to heat and light energy.
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The following diagram shows the bonds that make up potassium acetate.
Answer:
6
Explanation:
ye
How much energy is required to melt 2 kg of copper? Use the table below and
this equation: Q = mLfusion
A. 125.6 kJ
B. 9460 kJ
C. 414 kJ
D. 4730 kJ
Answer:
C. 414 kJ
Explanation:
Given parameters:
Mass of copper = 2kg
Unknown:
Amount of energy required to melt the copper = ?
Solution:
To solve this problem, we use:
Q = m L
m is the mass
L is the latent heat of fusion of copper = 207kJ/kg
So;
Q = 2 x 207 = 414kJ
30g of solute is dissolved in 100g of water. Calculate its % (m/m) concentration.
Answer:
23%
Explanation:
Turning on your X-Box is an example of___ energy turning into ___ energy.
A.electrical,nuclear
B.nuclear,sound
C.electrical,light
D.electrical,chemical
Answer:
electrical --> light
Explanation:
What coefficient will balance the equation that is shown?
Al +_ HCI-H2 + ALCI,
Balanced equation :
2Al +6HCI⇒ 3H₂ + 2AlCI₃
Further explanationGiven
Reaction (unbalanced)
Al +HCI⇒ H₂ + ALCI₃
Required
Balanced equation
Solution
Give a coefficient
aAl +bHCI⇒ cH₂ + AlCI₃
Al, left = a, right=1⇒a= 1
Cl, left = b, right=3⇒b=3
H, left = b, right=2c⇒b=2c⇒3=2c⇒c=3/2
The equation becomes :
Al +3HCI⇒ 3/2H₂ + AlCI₃ x 2
2Al +6HCI⇒ 3H₂ + 2AlCI₃
ILL GIVE YOU BRAIN LIEST IF YOU KNOW THE ANSWERS
Answer:B & C
tell me if im wrong
Answer:
Q 3 c it will reduce rate of photosynthesis in plants that live in the bottom of the lake
Q4 d the atom are in same group
This is right answer because these two elements are Lithium and neon Lithium is present in first group and Neon in last or group 18
Explanation:
some students using Apple to represent the Earth what is the best reason to use an Apple for this comparison?
Answer:
The skin of the apple is very thin, and the crust of the Earth is very thin.
I am listing the order starting with new moon.
New Moon
Waxing Crescent
first quarter
waxing gibbous
full moon
waning gibbous
last quarter
waning crescent
and new moon again.
Answer:
new Moon.
waxing crescent Moon.
first quarter Moon.
waxing gibbous Moon.
full Moon.
waning gibbous Moon.
last quarter Moon.
waning crescent Moon.
New moon
Explanation:
Your answer is correct
A 1.0 kg ball is thrown into the air and initial velocity of 30 mi./s how high into the air did the ball travel
Answer:
45.9m
Explanation:
Given parameters:
Mass of the ball = 1kg
Initial velocity = 30m/s
Unknown:
Height the ball will travel = ?
Solution:
At the maximum height, the final velocity of the ball will be 0;
Using ;
V² = U² - 2gh
V is the final velocity
U is the initial velocity
g is the acceleration due to gravity
h is the height
0² = 30² - (2 x 9.8 x h)
0 = 900 - 19.6h
h = 45.9m
What is the frequency of light with a wavelength of 3.2 x 10^-16 m?
Answer:
f = 0.94 ×10²⁴ Hz
Explanation:
Given data:
Frequency of light = ?
Wavelength of light = 3.2 ×10⁻¹⁶ m
Solution:
Formula:
Speed of light = wavelength × frequency
c = λ × f
c = speed of wave = 3×10⁸ m/s
by putting values,
3×10⁸ m/s = f × 3.2 ×10⁻¹⁶ m
f = 3×10⁸ m/s / 3.2 ×10⁻¹⁶ m
f = 0.94 ×10²⁴ s⁻¹
f = 0.94 ×10²⁴ Hz (Hz = s⁻¹)
How can you ensure the chemical reaction produces the right amount of heat in a hot pack without hurting you?
Answer:
Heat packs that contain iron and water packets: Exposing the solution to air results in the oxidation of the iron (creates rust). The oxidation of the iron is an exothermic process. Heat packs that contain supersaturated sodium acetate: These are reusable, the packs are boiled to dissolve sodium acetate.
Explanation:Thanks for asking question
consider an atom that has an electron in an exicted state . the electron falls to a lower energy level . what effects does that have on the electron ?
Answer:
Each time an excited helium atom falls back from an excited state to its ground state or to a lower energy state, it emits a photon of radiation that shows up as this specific line-emission spectrum.
Explanation:
Electrons are arranged in orbits called energy levels. The Gizmo shows all of the
first two energy levels but only part of the third energy level.
A. How many electrons can fit in the first energy level?
B. How many electrons can fit in the second energy level?
C. How many electrons fit in the part of the third energy level shown?
Answer:
A is 2, B is 8, and C is 18
Explanation:
I did the Gizmos
The two, eight, and eighteen electrons can be filled in the first, second, and third energy levels respectively.
What are the energy levels?The electrons revolve in different orbits are known as energy levels or stationary states. These energy levels are numbered as n = 1, 2, 3…… These values are also known as the principal quantum numbers.
The first energy level is also known as 'K' shell or level. The second energy level is called 'L' shell, the third energy level is 'M' shell, and so on.
The electrons present in the K shell contain the least energy whereas the levels contain more energy that is far from the nucleus.
The first energy level (n = 1) can have maximum two electrons in it. The second energy level ( n= 2) can have maximum eight electrons and the third energy level can fill maximum eighteen electrons in it.
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The element fluorine has an atomic number of
a. 10
b. 9
c. 19
d. 28
Answer:
B.9
Explanation:
Applying a force for a longer time increases the change in
(select all that apply)
Weight
Gravity
Velocity
Mass
Momentum
Answer:
velocity and momentum
Explanation:
as you exert force, the object accelerates, hence, its velocity increases.
since momentum is mass times velocity, the momentum increases too
Please be reminded, this answer may not be 100% correct
When the force should be applied for a long time so it increases the change in velocity and momentum
What is velocity and momentum?The momentum of the object should be equivalent to the object mass times with the object velocity
Here
p = mv
Here p means momentum
m means mass
v means velocity
Here the momentum should be directly proportional to the mass of the object and for the velocity of the object also.
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Cynthia has 200kg of magnesium. Calculate how much MgCl2 she can make.
Mg + Cl2 = MgCl2
Answer:
784.4kg
Explanation:
Given parameters:
Mass of Mg = 200kg
Unknown:
Mass of MgCl₂ = ?
Solution:
The reaction equation is given as:
Mg + Cl₂ → MgCl₂
Find the number of moles of the given specie;
Number of moles of Mg = [tex]\frac{mass}{molar mass}[/tex] = [tex]\frac{200000}{24.3}[/tex] = 8230.5mole
So;
1 mole of Mg will produce 1 mole of MgCl₂
8230.5mole of Mg will produce 8230.5mole of MgCl₂
Mass of MgCl₂ = number of moles x molar mass
Molar mass of MgCl₂ = 24.3 + 2(35.5) = 95.3g/mol
Mass of MgCl₂ = 8230.5mole x 95.3g/mol = 784.4kg
PLEASE HELP ADAP I WILL MARK AS BRAINLYEST
Answer:
c! Hope this helps!
Explanation:
BRAINLIEST PLZ ;)
Answer:
I think its the third one im not sure tho
Explanation:
2. Convert 120.02g of FrBiz to moles
a. 0.19 moles
b. 5.34 moles
c. 76,932.82 moles
Answer:
PRACTICE MULTIPLE CHOICE QUESTIONS FROM UNIT 10
1.) A cylinder is filled with 2.00 moles of nitrogen, 3.00 moles of argon, and 5.00 moles of helium. If
the gas mixture is at STP, what is the partial pressure of the argon?
(A) 152 torr (B) 228 torr (C) 380. torr (D) 760. torr
2.) Compared to the average kinetic energy of 1 mole of water at 0 oC, the average kinetic energy
of 1 mole of water at 298 K is
(A) the same, and the number of molecules is the same
(B) the same, but the number of molecules is greater
(C) greater, and the number of molecules is greater
(D) greater, but the number of molecules is the same
3.) If the pressure on a given mass of gas in a closed system is increased and the temperature
remains constant, the volume of the gas will
(A) decrease (B) increase (C) remain the same
4.) Which gas has approximately the same density as C2H6 at STP?
(A) NO (B) NH3 (C) H2S (D) SO2
5.) At a temperature of 273 K, a 400. milliliter gas sample has a pressure of 760. millimeters of
mercury. If the pressure is changed to 380. millimeters of mercury, at which temperature will
this gas sample have a volume of 551 milliliters?
(A) 100 K (B) 188 K (C) 273 K (D) 546 K
Get the answers to these questions
Back to the Unit 10 Old Tests Pag
Why do scientist use the scientific method
Answer:
B
Explanation:
scientists always look for evidence
Answer:
Yea its B
Explanation: The person above me legit toke the answer out of my mouth
The reaction of Pb+4 and O-2 produces the compound of
a
Pb2O2
b
PbO
c
Pb2O
d
PbO2
Answer:
Pb₂O₄
Explanation:
The given species are:
Pb⁴⁺ O²⁻
Now, to solve this problem, we use the combining powers which corresponds to the number of electrons usually lost or gained or shared by atoms during the course of a chemical combination.
Pb⁴⁺ O²⁻
Combining power 4 2
Exchange of valencies 2 4
Now the molecular formula is Pb₂O₄
What do the red arrows represent
Answer:
There are three forces acting on the skateboard. One of these forces is the weight of the rider. Another is the force of gravity on the board itself. The third is the force of the ground pushing up on the skateboard.
How do you measure density?
Density over mass
Mass over volume
Volume over density
Mass over density
Answer:
Mass over Volume........
A student performed an investigation to determine if the rate of photosynthesis in elodea is affected by a higher than normal concentration of carbon dioxide gas in the water in which the plant is growing. After increasing the concentration of carbon dioxide in water, the student illuminated the plant with a light and collected the bubbles of oxygen gas that were given off from the cut end of the submerged plant. In this investigation, what would be the best indicator of the rate of photosynthesis? a a change in the color of the plant b an increase in the length of the elodea plant over a period of 12 hours c the amount of light that is transmitted through the water d the amount of oxygen collected over a period of 12 hours
Answer:
D. the amount of oxygen collected over a period of 12 hours
Explanation:
Photosynthesis is a metabolic reaction performed by the cells of plant. In this reaction, light is used as an energy source to combine carbon dioxide (CO2) and water (H2O) to produce glucose and oxygen gas (O2) as products. In every chemical reaction including photosynthesis, an increase in concentration of reactants will increase the rate of the reaction, which is evident in the amount of products formed.
According to this question where a student is performing an investigation to determine the relationship between a higher than normal concentration of carbon dioxide gas and the rate of photosynthesis. After increasing the concentration of carbon dioxide in water, the student illuminated the plant with a light and collected the bubbles of oxygen gas that were given off from the cut end of the submerged plant.
Based on the above explanation, the best indicator of the rate of photosynthesis in this investigation will be THE AMOUNT OF OXYGEN COLLECTED OVER A PERIOD OF 12 HOURS.