Answer:
it was Millikan. He conducted the oil drop experiment. Thomson determined the electon charge not the quantity. Rutherford used the gold foil experiment to find positive charge and that most of the atom is empty space. Dalton proposed that matter was made of small particles called atoms but that was a concept already proposed by ancient greeks. Dalton also proposed the atomic theory.
<span>The region(s) of the periodic table which are
made up of elements that can adopt both positive and negative oxidation numbers
are the “non-metal” region. As we can see on the periodic table, the elements situated
at the right side of the table have two oxidation states, one positive and the
other a negative. </span>
The correct answer is B) Basic. Hope this helps.
<span>1. The correct option is A, THE OXYGEN ATOM HAS A NEGATIVE CHARGE. A water molecule is made up of two atoms of hydrogen and one atom of oxygen. The molecules of water are arranged in such a way that, the negative hydrogen atom is attracted to the positive hydrogen atom and the overall structure is bent. Because oxygen is more electronegative than hydrogen, oxygen atom draws the shared electrons toward itself , this gives the oxygen end of the molecule a partial negative charge and the hydrogen end, a partial positive charge.
2. The correct option is: WITHOUT THE PROPER BALANCE OF WATER, CHEMICAL REACTIONS WILL NOT TAKE PLACE. Metabolic chemical reactions take place in living cells all the time because water, which is a necessary condition for the reaction is in place. Th fluids find in the cells are mostly water; water creates suitable conditions for biochemical reactions to take place. Without water, the cells will not be able to carry out any chemical reaction.
3. The correct option is A. Hydrogen bond allows oxygen and water molecules to be bonded together. Hydrogen bonds are weak interactions that formed between the hydrogen with a patial positive end and oxygen with a patial negative end. The hydrogen bond in water is responsible for the unique properties associated with water.</span><span />
Answer:
pH = 12.22
Explanation:
<em>... To make up 170mL of solution... The temperature is 25°C...</em>
<em />
The dissolution of Barium Hydroxide, Ba(OH)₂ occurs as follows:
Ba(OH)₂ ⇄ Ba²⁺(aq) + 2OH⁻(aq)
<em>Where 1 mole of barium hydroxide produce 2 moles of hydroxide ion.</em>
<em />
To solve this question we need to convert mass of the hydroxide to moles with its molar mass. Twice these moles are moles of hydroxide ion (Based on the chemical equation). With moles of OH⁻ and the volume we can find [OH⁻] and [H⁺] using Kw. As pH = -log[H⁺], we can solve this problem:
<em>Moles Ba(OH)₂ molar mass: 171.34g/mol</em>
0.240g * (1mol / 171.34g) = 1.4x10⁻³ moles * 2 =
2.80x10⁻³ moles of OH⁻
<em>Molarity [OH⁻] and [H⁺]</em>
2.80x10⁻³ moles of OH⁻ / 0.170L = 0.01648M
As Kw at 25°C is 1x10⁻¹⁴:
Kw = 1x10⁻¹⁴ = [OH⁻] [H⁺]
[H⁺] = Kw / [OH⁻] = 1x10⁻¹⁴/0.01648M = 6.068x10⁻¹³M
<em>pH:</em>
pH = -log [H⁺]
pH = -log [6.068x10⁻¹³M]
<h3>pH = 12.22</h3>
