Answer:
Tristan wraps some gifts and then brings them to the post office where they are delivered to people in different parts of the country. Which organelle is Tristan most like?
Answer:
The answer is surface tension.
Explanation:
The high surface tension helps the paper clip - with much higher density - float on the water. The cohesive forces between liquid molecules are responsible for the phenomenon known as surface tension. hope this helps :)
Answer:
230
Th
90
Explanation:
The left side shows the element uranium with mass number 234 (superscript to the left of ths symbol) and atomic mass 92 (subscript to the left of the symbol).
So, you have to find the mass number and atomic numbers missing on the right side which added to those shown for the helium atom reach 234 and 92.
This the the mathematics:
1) Mass number of U - mass number of He = 234 - 4 = 230 ⇒ the mass number of the missing element is 230.
2) atomic number of U - atomic number of He = 92 - 2 = 90 ⇒ the atomic number of the missing element is 90.
Now, you use the atomic mass to identify the element. You do it by simply searching in a periodic table. There you find that the atomic number 90 corresponds to thorium, whose symbol is Th.
Now you have that the product that completes the right side of the decay equation is:
230
Th
90
A reaction is first order. If the initial reactant concentration is 0.0200 M, and 25.0 days later the concentration is 6.25 x 10-4 M, then its half-life is:
