If you cut the cube and keep all the pieces you are causing only physical change
Answer:
You may be referring to the gas that makes up 21% of the earth's atmosphere, which is oxygen.
Explanation:
According to NASA, the gases in Earth's atmosphere include:
Nitrogen — 78 percent
Oxygen — 21 percent
Argon — 0.93 percent
Carbon dioxide — 0.04 percent
(Trace amounts of neon, helium, methane, krypton and hydrogen, as well as water vapor)
After 100years, sample is 250g
After 200 years, sample is 125g
After 300years, sample is 62.5 g
Answer:

Explanation:
You don't give the reaction, but we can get by just by balancing atoms of Na.
We know we will need the partially balanced equation with masses, moles, and molar masses, so let’s gather all the information in one place.
M_r: 142.04
2NaOH + … ⟶ Na₂SO₄ + …
n/mol: 0.75
1. Use the molar ratio of Na₂SO₄ to NaOH to calculate the moles of NaF.
Moles of Na₂SO₄ = 0.75 mol NaOH × (1 mol Na₂SO₄/2 mol NaOH
= 0.375 mol Na₂SO₄
2. Use the molar mass of Na₂SO₄ to calculate the mass of Na₂SO₄.
Mass of Na₂SO₄ = 0.375 mol Na₂SO₄ × (142.04 g Na₂SO₄/1 mol Na₂SO₄) = 53 g Na₂SO₄
The reaction produces
of Na₂SO₄.
People use data tables and graphs in many financial careers and when looking at the statistics for something as simple as what they saw on the news, etc. When scientists use them, they’re both using them to see the numbers and the facts. They’re both able to use graphs and data tables to help them. They are different though because scientists use them for science related things like how much a tree grew in a year while everyday people use them to see the average amount of drop outs per year or something along those lines.
Data tables and graphs are very vital to a scientists job. They help them easily collect and organize information to where anyone can read it. It may not be absolutely necessary, but it’s something every scientist uses.
Any scientist doing any sort of research would use them. Whether they’re a biologist, geologist or whatever, they all use graphs and data tables to help them organize their research.