Answer:
A longitudinal study is a observational study that follows the same subjects repeatedly over a period of time, in some cases from birth to death
or
the same adults are tested at each time point: 20, 30, and 40 years of age
Answer:
See explanation for details
Explanation:
ammonium sulfate and barium nitrate Answer
Ba2+(aq) + SO4^2-(aq) ----------> BaSO4(s)
lead(II) nitrate and sodium chloride Answer
Pb2+(aq) + 2Cl-(aq) -----------> PbCl2(s)
copper(II) chloride and sodium hydroxide Answer
Cu2+(aq) + 2OH-(aq) -------------> Cu(OH)2(s)
There can only be a net ionic reaction when a precipitate is formed as the two solutions are mixed together.
Answer:
reactivity
Explanation:
a chemical reacting to another chemical is considered a Chemical property because chemicals react with other chemicals differently
Answer:
The number of atoms in 1 mole silver is also 6.022 *10^23 atoms.
Option C is correct.
Explanation:
Step 1: Data given
Mass of 1 mole silver = 107.9 grams
Step 2: Calculate the number of atoms in 1 mole of silver
To calculate the number of atoms in 1 mole, we multiply the number of Avogadro by the number of moles
Number of atoms = 1 mol * 6.022 *10^23 atoms/ mol
Number of atoms = 6.022 * 10^23 atoms
Since the number of Avogadro says there are 6.022 * 10^23 atoms per 1 mole. The number of atoms in 1 mole silver is also 6.022 *10^23 atoms.
Option C is correct.
Answer:
Number of neutrons: 44
Number of protons: 34
Number of electrons: 36
Explanation:
The atomic number of Se (Selenium) is 34
Mass number is 78
Number of neutrons = mass number - atomic number = 78 - 34 = 44
Number of protons is the same as the atomic number
Number of protons = 34
Selenium ion has a charge of -2. This means it accepts two more electrons
Number of electrons = atomic number + 2 = 34 + 2 = 36
