This problem is honestly, very easy. Just grab a periodic table and find the element in Group 1 and Period 7. But first, let's discuss how the elements are arranged systematically in a periodic table. There are a lot of scientists who contributed to it, but the most famous one is Dimitri Mendeleev. He arranged the elements according to their atomic number. The elements starts from 1 which is Hydrogen up to the heaviest known elements which is Oganesson with an atomic number of 118. As you can observe, there is a gap between groups 3 and 4. This is done so that the periodic table does not take too much space horizontally. Thus, they are just placed at the bottom. These elements are called lanthanides (upper row) and actinides (lower row). The rows in the periodic table are called groups, and the columns are called periods.
Now, the element at the lower left corner (Group 1, Period 7) is Francium, abbreviated as Fr. It has an atomic number of 87. Some elements are actually synthesized, but Francium is a naturally occurring radioactive element. It was discovered by Marguerite Perey in France.
Answer:I believe it is the Senate
Explanation:
Answer:
2.7 g/cm³
Explanation:
Step 1: Calculate the mass of kerosene
The mass of the full beaker (mFB) is equal to the sum of the masses of the empty beaker (mEB) and the mass of the kerosene (mK).
mFB = mEB + mK
mK = mFB - mEB
mK = 60 g - 20 g = 40 g
Step 2: Calculate the density of kerosene
Density (ρ) is an intrinsic property of matter. It can be calculated as the quotient between the mass of kerosene and its volume.
ρ = m/V
ρ = 40 g/15 cm³ = 2.7 g/cm³
Answer: Drinking water with levels of nitrate at or below 10 mg/L is considered safe for everyone.
Explanation:
The U.S. Environmental Protection Agency (EPA) standard for nitrate in drinking water is 10 milligrams of nitrate (measured as nitrogen) per liter of drinking water (mg/L).