Please help it’s due asap I WILL GIVE BRAINLIEST

How does beta decay affect the atomic number?

MA_775_DIABLO [31]

The atomic mass number does not change because a beta particle has a much smaller mass than the atom. The atomic number goes up because a neutron has turned into an extra proton. Beta decay is fundamentally different from alpha decay. An alpha particle is made of two protons and two neutrons.

6 0

3 years ago

How many core electrons are in a ground state atom of selenium?

Harman [31]

Electrons in an atom can be classified as core electrons and valence electrons. Valence electrons are those electrons which are present in valence shell and participates in bond formation. While, Core electrons are all remaining electrons which are not present in valence shell, hence not take part in bonding.

Atomic number of Selenium (Se) is 34 hence it has 34 electrons with following electronic configuration;

1s², 2s², 2p⁶, 3s², 3p⁶, 4s², 3d¹⁰, 4p⁴

From electronic configuration it is found that the valence shell is 4, and the number of electrons present in valence shell are 6. So,

Core Electrons = Total Electrons - Valence Electrons

Core Electrons = 34 - 6

Core Electrons = 28

Result:
There are 28 core electrons in Selenium.

3 0

3 years ago

A chemist prepares a solution of copper(II) sulfate CuSO4 by measuring out 31.μmol of copper(II) sulfate into a 150.mL volumetri

baherus [9]

Answer:

The concentration of the copper (II) sulfate solution is 2.06 * 10^2 μmol/L or 2.06 * 10^2 μM

Explanation:

The concentration of a solution is the amount of solute dissolved in a given volume of solution. In this case, the concentration of the copper(II) sulfate solution in micromoles per liter (symbol ) is the number of micromoles of copper(II) sulfate dissolved in each liter of solution. To calculate the micromoles of copper(II) sulfate dissolved in each liter of solution you must divide the total micromoles of solute by the number of liters of solution.

Here's that idea written as a formula: c= n/V

where c stands for concentration, n stands for the total micromoles of copper (II) sulfate and V stands for the total volume of the solution.

You're not given the volume of the solution in liters, but rather in milliliters. You can convert milliliters to liters with a unit ratio: V= 150. mL * 10^-3 L/ 1 mL = 0.150 L

Next, plug in μmol and liters into the formula to divide the total micromoles of solute by the number of liters of solution: c= 31 μmol/0.150 L = 206.66 μmol/L

Convert this number into scientific notation: 2.06 * 10^2 μmol/L or 2.06 * 10^2 μM

3 0

2 years ago

HEEEEELP ASAPP IM AWARDING 30 points!!!!

alexira [117]

Answer:

$\rm S^{2-}$ .

Explanation:

Based on the electron configuration of this ion, count the number of electrons in this ion in total:

$2 + (2 + 6) + (2 + 6) = 18$ .

Each electron has a charge of $(-1)$ .

Atoms are neutral and have $0$ charge. However, when an atom gains one extra electron, it becomes an ion with a charge of $(-1)$ . Likewise, when that ion gains another electron, the charge on this ion would become $(-2)$ .

The ion in this question has a charge of $(-2)$ . In other words, this ion is formed after its corresponding atom gains two extra electrons. This ion has $18$ electrons in total. Therefore, the atom would have initially contained $18 - 2 = 16$ electrons. The atomic number of this atom would be $16$ .

Refer to a modern copy of the periodic table. The element with an atomic number of $16$ is sulphur with atomic symbol $\rm S$ . To denote the ion, place the charge written backwards (" $2-$ " for a charge of $(-2)$ ) as the superscript of the atomic symbol:

$\rm S^{2-}$ .

5 0

3 years ago

Read 2 more answers

Spell out the full name of the compound.

Talja [164]

Answer:

2–methyl–3–propylheptane.

Explanation:

The name of the compound can be obtained as follow:

1. Identify the functional group of the compound.

2. Determine the name of the compound by determining the longest continuous carbon chain.

3. Identify the substituent group attached.

4. Locate the position of the substituent group by giving it the lowest possible count. Where there are two or more different substitutent group attached to the compound, name them alphabetically.

5. Name the compound by combining

the above steps.

Thus, we can name the compound as follow:

1. The compound has only single bond. Therefore, the compound is an alkane.

2. The longest continuous carbon chain is 7. Therefore, the parent name of the compound is heptane.

3. The substitutent groups attached are:

Propyl i.e –C3H7

Methyl i.e –CH3

4. The substituent groups are located at:

Propyl i.e –C3H7 is located at carbon 3.

Methyl i.e –CH3 is located at carbon 2.

5. The name of the compound is:

2–methyl–3–propylheptane.

6 0

3 years ago