potassium, k, has an atomic number of 19 and an atomic mass of 39 how many electrons does a neutral atom of K have?

Plants and animals use different energy storage molecules, yet they both use the same mechanism to "burn" their stored energy. H

jek_recluse [69]

Answer:

The breaking of the chemical bonds of a storage molecule transfer energy, no what molecule is stored.

Explanation:

Being successful of plants and animals does not necessary depend on the stored molecule but on the energy being transferred during their breaking.

8 0

3 years ago

Which answer best explains the relationship between size and mass of the sun?

gizmo_the_mogwai [7]

The mean radius of the sun is 432,450 miles (696,000 kilometers), which makes its diameter about 864,938 miles (1.392 million km). You could line up 109 Earths across the face of the sun. The sun's circumference is about 2,713,406 miles (4,366,813 km). The total volume of the sun is 1.4 x 1027 cubic meters.

3 0

3 years ago

What is the mass number of an atom that has six protons , six electrons and eight neutrons

Tresset [83]

Answer:

14

Explanation:

Given parameters:

Number of protons = 6

Number of electrons = 6

Number of neutrons = 8

Unknown:

Mass number = ?

Solution:

The mass number of an atom is the sum of protons and neutrons in an atom;

Mass number = number of protons + number of neutrons

Mass number = 6 + 8 = 14

7 0

2 years ago

Most solids

Daniel [21]

Most solids a) are dense and difficult to compress.

Most solids are closely compacted, their molecules are close together and vibrate. They don't move freely like gas or water molecules do.
They are difficult to be squeezed or flattened.

6 0

2 years ago

2. (2 points) Calculate the Effective Nuclear Charge for each atom. Show all of your work for full credit. Se: Br: (1 point) Whi

Lera25 [3.4K]

The question is incomplete. Here is the complete question.

Consider the selenium atom, Se, and the bromine atom, Br.

Write out the full electron configuration fro each atom.

Se:

Br:

Calculate the Effective Nuclear Charge for each atom. Show all of your work for full credit.

Se:

Br:

Which atom is larger?

Answer and Explanation: Electron Configuration of an atom demonstrates the shape and energy of its electrons. One of the rules used for it is given by using Madelung's Rule, in which the order of increased energy of the electrons is:

1s < 2s < 2p < 3s < 3p < 4s < 4p < 5s < 6s < 4f < 5d < 6p < 7s < 5f < 6d < 7p

Atom of Selenium (Se) has 34 electrons. Its electron configuration is

Se: $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^{10}4p^{4}$

Atom of Bromine has 35 electrons. Its electron configuration is

Br: $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^{10}4p^{5}$

Effective Nuclear Charge ( $Z_{eff}$ )is the net positive charge experienced by an electron in a multi-electron atom. In other words, it is the net force that helds nucleus and electrons together.

It is calculated by: $Z_{eff}=Z-S$

where

Z is the atomic number, i.e., number of protons of the atom

S is the nonvalence electrons, i.e., the number of electrons between the nucleus and the electron in question.

For Selenium (Se):

From the electron configuration, the valence shell is 4 with 6 valence electrons. Nonvalence electrons is the difference between valence and total electrons:

S = 34 - 6 = 28

$Z_{eff}=34-28$ = 6

The Effective Nuclear Charge of Se is 6

For Bromine (Br):

The valence shell, according to the configuration, is 4 and valence electrons are 7.

S = 35 - 7 = 28

$Z_{eff}=35-28$ = 7

The Effective Nuclear Charge fo Br is 7.

Bromine is larger than Selenium because it has bigger Effective Nuclear Charge, which means it held its electrons more loosely and, consequently, has a larger atomic radius.

7 0

2 years ago