Did you mean significant figures? If so, 67.6(1.2)=81
When multiplying, you always leave the the answer in the least amount of significant figures.
Answer:
Direct evidence from rock samples and indirect evidence from seismic waves may account for why scientists have two ways of thinking about earth's layers
Explanation:
Scientists who study about the earth's structure and components called geologists have two main types of evidence to learn about Earth's interior namely
1. direct evidence from rock samples
2. indirect evidence from seismic waves
Direct evidence From Rock Samples
Scientists examine rocks from inside the Earth and these rocks give them clues about Earth’s structure. Some scientists have drilled holes as much as 12 kilometers into Earth and bring up samples of rock. From these samples, they can make inferences about conditions deep inside Earth, where these rocks formed. In addition, forces inside Earth sometimes blast rock to the surface from depths of more than 100 kilometers. These rocks from deep within the Earth provide more information about the interior.
Indirect evidence From Seismic Waves
Since scientist cannot look inside Earth, they have devised an indirect methods of observation by using seismic waves. When earthquakes occur, they produce seismic waves. Scientists record the seismic waves and study how they travel through Earth. The speed of seismic waves and the paths they take reveal the structure of the planet. Using data from seismic waves, scientists have learned that Earth’s interior is made up of several layers with each layer surrounding the layers beneath it.
Answer:
Hey there.. the question is not proper. Please give the whole question
Answer:
22387Fr→22388Ra+0−1e+00ν
Explanation:
β-decay is the decay of a neutron into a proton, which keeps the total mass the same, but increases the number of protons by 1. β-decay does this by releasing an electron, which conserves charge, and a neutrino.
Francium-223 has an atomic number of 87, so is written as
22387Fr
If the atomic number then increases by 1 to become 88, then it is a new element. Looking at the periodic table, element 88 is radium, Ra.
In the form of an equation, this is shown as
22387Fr→22388Ra+0−1e+00ν
You can check this is correct by adding up the top numbers on each side and equating them, and doing the same with the bottom numbers.
223=223+0+0
87+88+(−1)+0
