Scientific notation is defined as writing a number between 0 to 10 multiplied by a power of 10
3.5 x 10² x 8.0 x 10⁻²
when we solve the equation
answer - 28
to write in scientific notation the decimal point should come after the first digit from the right. to bring the decimal point from after digit 8 to after digit 2, we have to move one decimal place to the left. then we get 2.8, to get the value as 28 we have to multiply 2.8 by 10
therefore answer is
2.8 x 10¹
The only solution you'll need to have for this problem is a periodic table. The columns in the table are called groups, and they are number from the left to the right starting with 1. The rows in the table are called periods which are numbered from the top to bottom starting with 1.
6. Elements that belong to the same group portray similar chemical properties. Therefore, the element in period 4 which is also in group 2 is
<em>Calcium (Ca)</em>.
7. The elements that are striked through with the red slanting lines are the metalloids. All the elements to the left of the metalloids are metals. All the elements to the right are nonmetals. Bromine has a symbol of Br. Since At is a metalloid and located in the same group with Br, the
<em>answer is Astatine (At).</em>8. Tin has the chemical symbol of Sn. The nonmetal that is located in the same group is
<em>Carbon (C)</em>.
9. All the elements in period 6 would have similar properties. The answers could be:
<em>Phosphorus (P), Arsenic (As), Antimony (Sb) and Bismuth (Bi)</em>.
10. Period is row 1 and group 18 is the last column.
<em>The answer is Helium (He).</em>
The molar mass of Na₂SO₄ -
2 x Na - 2 x23 = 46
1 x S - 1 x 32 = 32
4 x O - 4 x 16 = 64
total = 46 + 32 + 64 = 142 g/mol
the molarity of solution - 2.0 M
in 1 L of solution , 2.0 moles
Therefore in 2.5 L - 2 mol/L x 2.5 L = 5 mol
then the mass of Na₂SO₄ required = 142 g/mol x 5 mol = 710 g
To determine the heat or energy needed for the process, we use the equation,
H = mcpdT
where m is the mass, cp is the specific heat and dT is the temperature difference.
H = (95.4g)(0.44 J/g°C)(32°C - 22°C)
= 419.76 J
Thus, the amount of heat that should be ABSORBED is approximately 419.76 J.
Reacting 1-chloro-2-ethylcyclohexene with hydrogen gas using a platinum catalyst would give a product of 1-chloro-2-ethylcyclohexane.
Hydrogen gas is a reducing agent, which in this reaction, simply mean that the alkene double bond in the cyclohexene will disappear because one of the two bonds forming the double bond (in the alkene) will be connected to a hydrogen atom. The platinum catalyst is necessary to allow the reaction to proceed at a much lower (activation) energy than would have been required.