Answer:
Option C. 2 half lives.
Explanation:
The following data were obtained from the question:
Original amount (N₀) = 1000 atoms
Amount remaining (N) = 250 atoms
Number of half-lives (n) =?
Half-life is defined as the time taken for the substance to reduce to half its original side. Mathematically, it can be obtained as follow:
N = 1/2ⁿ × N₀
N is the amount remaining.
n is the number of half-lives.
N₀ is the original amount.
Using the above formula, we can obtain the number of half-lives as follow:
Original amount (N₀) = 1000 atoms
Amount remaining (N) = 250 atoms
Number of half-lives (n) =?
N = 1/2ⁿ × N₀
250 = 1/2ⁿ × 1000
Cross multiply
250 × 2ⁿ = 1000
Divide both side by 250
2ⁿ = 1000/250
2ⁿ = 4
Express 4 in index form
2ⁿ = 2²
n = 2
Therefore, it will take two (2) half lives for the amount to get to 250 atoms.
Which model of the solar system has Earth at the center of the revolving planets and stars? An example model is shown
below. A geocentric
B heliocentric
C Newtonian
D mercurian
Answer:
The geocentric model of the solar system has Earth at the center.
Explanation:
Throughout history, there have been multiple different models that humans thought of or created through observation. The two most famous ones from the past are the geocentric and heliocentric, with the geocentric coming earlier and for a very long time being the model that was accepted by the majority.
The geocentric model is a model that puts Earth in the center of the universe. Earth is presented as the most important and largest object in the universe. All of the space bodies, the Sun, stars, Moon, planets, were thought to revolve around Earth. As it turned out, this model was full of mistakes. Everything about it was wrong, with the only correct thing being that the Moon is actually revolving around Earth.
Most people in Africa earn their living by
A. working in service industries
B. farming and herding
C. working in factories
D. mining for gold and other resources
Please select the best answer from the choices provided
Answer:
B. farming and herding
Explanation:
More than half of Africa's people make their living from farming. Although its total harvest has climbed over the past few decades, this is mainly because there are more people farming more land. But in many places there is no spare land to farm.
hope i helped
HOW DOES ALTITUDE AFFECT YOUR BREATHING?
Answer:
In higher altitudes, the air is usually colder, less dense, and has less oxygen molecules. This means that if you were there, you would need to take more breaths to get the same amount of oxygen as you would at lower altitudes. Higher elevation makes it even harder to breathe.
Explanation:
Hope this info helps!
10 points for correct answer
Which of the following describes how scientists separate the physical layers of the Earth?
Group of answer choices
A Based on how the layers interact with each other
B Based on the size of each layer
C Based on the color of each layer
D Based on the atoms and molecules in each layer
D Based on the atoms and molecules in each layer
A segment has midpoint at (2,-4) and an endpoint at (5,-9). What are the coordinates of the other endpoint?
Answer:
The coordinates of the other endpoint are (-1,1).
Explanation:
Mid point = (2,-4)
One endpoint = (5,-9)
We need to find the coordinates of the other mid points. Let it is (x₂,y₂). Using the mid point formula to find it.
[tex]\text{Mid-points}(x_m,y_m)=(\dfrac{x_1+x_2}{2}, \dfrac{y_1+y_2}{2})[/tex]
We have, [tex]x_m=2, y_m=-4, x_1=5, y_1=-9[/tex]
[tex]\text{Mid-points}(2,-4)=(\dfrac{5+x_2}{2}, \dfrac{(-9)+y_2}{2})\\\\\dfrac{5+x_2}{2}=2\ \text{and}\ \dfrac{y_2-9}{2}=-4\\\\5+x_2=4\ \text{and}\ y_2-9=-8\\\\x_2=-1\ \text{and}\ y_2=1[/tex]
So, the coordinates of the other endpoint are (-1,1).
I neeeeeed help plzzzzz
Answer:
a
Explanation:
because it is tilted away from the suns rays
Geographers identify climates by looking at temperature, precipitation and _____________.(this is in geography btw and i will give branlist)
Answer:
native plant life.
Need the answer to the first part of the question
Answer:
Constructive Forces
Explanation:
The tectonic plates are doing the construction of the mountains and land formations.
Active volcanoes are most likely to form at or near-
A. Transform plate boundaries
B. A convergent continental continental plate boundary
C. The center of the continents
D. A conversion oceanic continental continental plate boundary( subduction boundaries)
Answer:
A convergent oceanic-continental plate boundary (subduction boundaries).
Explanation:
Volcanoes form two types of plate boundaries, but also in the interior of the continental plates where there are hot spots below. The two types of plate boundaries where volcanoes can be found are the convergent and divergent plate boundaries, with the first ones having the vast majority of the volcanoes above the surface, while the second ones have the vast majority below the water surface.
At convergent plate boundaries, especially where continental and oceanic plates collide, there are volcanoes all across the plate boundary. This is due to the formation of a subduction zone, where the crust gest much more fragile around it and magma manages to push through and come out on the surface very easily. In practice, this can easily be seen by the fact that the majority of the volcanoes are found in the so-called ''Ring of Fire'' where there are numerous convergent boundaries between continental and oceanic plates.
PLEASE ANSWER, TAKING THE EXAM REVIEW ON EDGE
Pull factors are __________.
A.
reasons to leave a place
B.
pieces of culture that spread from place to place
C.
reasons to go to a new place
D.
forces that make a person move involuntarily
Please select the best answer from the choices provided
A
B
C
D
Answer:
Pull factors are positive factors that attract people to new areas from other areas. A booming job market is a pull factor because many people seek jobs in order to provide for their family. Push factors are negative factors that deter people from their original locale.
Explanation: im 99% positive its C
Answer:
c
Explanation:
an A+ for you
Which two Canadian Provinces are in the United Province of Canada?
O Ontario
o Quebec
O Vancouver
O Nova Scotia
Answer:
A and B
Explanation:
