Which of the following elements is chemically similar to Oxygen?
a. flourine
b. nitrogen
c. Sulfur
d. Hydrogen
Which of the following is smallest?
a. proton
b. electron
c. neutron
d. nucleus
The number "a million trillion" can also be written as 1015
True
False
Our Milky Way galaxy contains perhaps 400 billion stars. Suppose that 0.05% (i.e., 0.0005) of these stars have planetary systems containing at least one Earthlike planet (one that could conceivably support Earthlike life). Express this number in words (thousands or millions, etc.).
a. 200 million
b. 200 thousand
c. 20 billion
d. 20 thousand
1. http://www.webelements.com/
Look for the element in the same column as oxygen, element # 8.
2. http://www.krysstal.com/subatomic.html
mass of electron, proton, neutron in a table.
3. What do you think? That looks like one thousane fifteen to me.
4. 400 billion x 0.0005 = 200,000,000.
2,000 is 2 thousand.
2,000,000 is 2 million.
200,000,000 is _____________.
200 million
1. To determine which element is chemically similar to Oxygen, you can use the periodic table. One option is to visit the website http://www.webelements.com/ and look for the element in the same column as Oxygen, which has an atomic number of 8.
2. To find out which of the given options is the smallest, you can refer to a source that provides information about the subatomic particles. One option is to visit the website http://www.krysstal.com/subatomic.html, which presents a table with the masses of electrons, protons, and neutrons.
3. In this case, the statement 1015 being equivalent to "a million trillion" is false. To express this number in words, you can break it down into its components. "10" is read as "ten," and the exponent "15" corresponds to "quadrillion."
4. To calculate the number of stars with planetary systems containing at least one Earthlike planet, you can multiply the total number of stars in the Milky Way galaxy (400 billion) by the percentage (0.05%). This gives you 400,000,000 x 0.0005 = 200,000. To express this number in words, it would be "200 thousand."