. If 69.15% exists as 63Cu with an atomic mass of 62.92, then what is the atomic mass of the second isotope?

alexandr1967 [171]

Answer:

The statement that best describes the trend in first ionization enery of elements on the periodic table is:

It generally decreases down a group because valence electrons are farther from the nucleus.

The first ionization energy measures how difficult is to release an electron from the outermost shell. The higher the ionization energy the more difficult it is to release an electron, the lower the ionication energy the easier to release an electron.

As the atomic number of the atom increases (which is what happens when you go down a group) the furthest the outermost shell of electrons will be (the size of the atoms increases) and so those electrons require less energy to be released, which means that the ionization energy decreases.

Hope it helps!

4 0

3 years ago

Read 2 more answers

What is the number of moles of ammonia gas formed when 0.5 mole of nitrogen gas is reacted with excess of hydrogen gas?

Troyanec [42]

Answer: 1.5mol NH3

Explanation: 1N2+3H2= NH3

0.5 mol N2x 3NH3/1molN2= 0.5x3= 1.5mol NH3

7 0

2 years ago

Behavior (defense mechanisms)definition

Gekata [30.6K]

A variety of usually unconscious mental processes used to protect oneself from shame, anxiety, loss of self-esteem, conflict, or other unacceptable feelings or thoughts, and including behaviors such as repression, projection, denial, and rationalization.

(google)

7 0

3 years ago

What is the difference between hypertonic and hypotonic

Bess [88]

Answer: A solution will be hypertonic to a cell if its solute concentration is higher than that inside the cell, and the solutes cannot cross the membrane. If a cell is placed in a hypotonic solution, there will be a net flow of water into the cell, and the cell will gain volume.

Picture:
Meaning of hypertonic: (1): having a higher osmotic pressure than a particular fluid, typically a body fluid or intracellular fluid. (2) of or in a state of abnormally high muscle tone.

5 0

3 years ago

You wish to measure the iron content of the well water on the new property you are about to buy. You prepare a reference standar

djverab [1.8K]

1.04 ⨯ 10 $^{-4}$ M

<h3>Explanation</h3>

A = ε $\cdot l \cdot c$ by the Beer-Lambert law, where

A the absorbance,
$l$ the path length,
ε the molar absorptivity of the solute, and
$c$ concentration of the solution.

A and ε are the same for both solutions. Therefore, $l \cdot c$ is constant; $l$ is inversely proportional to $c$ . The 100 mL sample would have a concentration 1/4.78 times that of the 45.0 mL reference.

The 13.0 mL standard solution has a concentration of 5.17 ⨯ $10^{-4}$ M. Diluting it to 45.0 mL results in a concentration of $5.17 \times 10^{-4} \times \frac{13.0}{45.0} =$ 1.494 M.

$c$ is inversely related to $l$ for the two solutions. As a result, c₂ = $c_1 \cdot \frac{l_1}{l_2} = 1.494 \times 10^{-4} \times \frac{1}{4.78} =$ 3.126 M.

The 30.0 mL sample has to be diluted by 30.0 / 100.0 times to produce the 100.0 mL solution being tested. The 100.0 mL solution has a concentration of 3.126 M. Therefore, the 30.0 mL solution has a concentration of $3.126 \times \frac{100.0}{30.0} =$ 1.04 ⨯ $10^{-4}$ M.

6 0

3 years ago