All categories

3 years ago

PLEASE HELP!!

Chemistry

2 answers:

Alex17521 [72]3 years ago

6 0

Answer:

Rb is an alkali metal.

Explanation:

The elements characterized by having a single electron in its outermost orbital (s) are called alkali metals or simply alkaline metals.

Due to the presence of this electron, they are chemically very reactive because they have a tendency to lose this electron. In other words, their high reactivity is due to the fact that they form chemical bonds with many types of substances and elements and do so easily. This is due to its high electronegativity.

Like all metals, they are very good thermal and electrical conductors. But in comparison, alkali metals are soft and have a low melting point due to their metallic bond. This link is quite weak because it is the external electrons that are responsible for the bond and in these metals there is only one electron per atom.

The alkali metals are located in group 1 of the periodic table and are: lithium (Li), sodium(Na), potassium(K), rubidium(Rb), cesium(Cs) and francium(Fr).

Musya8 [376]3 years ago

4 0

Rubidium is a alkali metal.

You might be interested in

Look at the dots around each symbol and the energy levels from the resources above;

Anton [14]

Hello! Here's the answer I was able to come up with:

Why does Na have only one dot?

Sodium, or Na, has only one valence electron. (This makes the atom tend to participate in ionic bonding and "give" its single valence electron to an atom like chlorine.)

Why do none of these diagrams show more than 8 dots?

It is physically impossible for an atom to have more than 8 electrons in its valence layer, according to the Octet Rule.

What relationship do you notice between the dots in these two charts?

The dot diagram for each element represents the number of electrons each element will have in its outermost, or valence, shell. (2-8-8)

The number of dots that hydrogen and helium have in their dot diagram is the same as the number of electrons shown for them on the Periodic Table. Why?

An atom can have a maximum of two electrons in its innermost layer. Hydrogen and helium have only one and two electrons, respectively, so they don't have enough electrons to actually have more than one layer. Therefore, their outermost layer is, in fact, their only layer. This is why the number of dots that hydrogen and helium have in their dot diagram is the same as the number of electrons shown for them on the Periodic Table.

Don't copy this word for word! You will most likely be in trouble for plagiarism. Instead, rewrite these ideas in your own words, or paraphrase. Good luck, and I know you can do it! ♥

6 0

3 years ago

A microwave can have a frequency of 3.8 X 1010Hz. How much energy does this microwave give off in joules?

Marina86 [1]

Answer:

2.52 x $10^{-23}$ J

Explanation:

The energy given off by the microwave can be determined by the application of Planck's energy formula:

E = hf

where: E is the required energy, h is Planck's constant (6.626 x $10^{-34}$ $m^{2}$ Kg/s), and f is the frequency (3.8 x $10^{10}$ Hz).

So that;

E = 6.626 x $10^{-34}$ x 3.8 x $10^{10}$

= 2.51788 x $10^{-23}$

Therefore, the energy released by the wave is 2.52 x $10^{-23}$ J.

3 0

3 years ago

lassify these bonds as ionic, polar covalent, or nonpolar covalent. Ionic Polar covalent Nonpolar covalent

jarptica [38.1K]

The question is incomplete, complete question is:

Classify these bonds as ionic, polar covalent, or nonpolar covalent.

Na-F

P-Cl

Cl-Cl

Answer:

Na-F : The bond present is ionic bond.

PCl : The bond present is polar covalent bond.

ClCl : The bond present is non polar covalent bond.

Explanation:

1) Ionic bonds are defined as the bonds which are formed by the complete transfer of electrons from cation (positively charged ions) to anion (negatively charged ions). For Example: NaCl, $BaSO_4$ etc.

Ionic compound :This compound is formed when difference in electronegativity between the atoms is very large.

2) Covalent bond is defined as the bond which is formed by the sharing of electrons between the atoms. For Example: HCl, $CH_4$ etc.

Polar covalent compound: This compound is formed when difference in electronegativity between the atoms is present. When atoms of different elements combine, it results in the formation of polar covalent bond. For Example: $CO_2,NO_2$ etc..

Non-polar covalent compound: This compound is formed when there is no difference in electronegativity between the atoms. When atoms of the same element combine, it results in the formation of non-polar covalent bond. For Example: $N_2,O_2$ etc.

Na-F : Two different atoms with high electronegativity difference

Ionic compound because sodium is metal and fluorine is non metal and the difference between their electronegativity is very large.The bond present is ionic bond.

PCl : Two different atoms with low electronegativity difference

Polar covalent compound because phosphorus and fluorine both are non metal and the difference between their electronegativity is not very large.The bond present is polar covalent bond.

ClCl : Two same atoms with nil electronegativity difference.

Non Polar covalent compound because both are chlorine atom (non metal) and the difference between their electronegativity is zero.The bond present is non polar covalent bond.

5 0

3 years ago

Express the pressure 545 mm Hg in kilopascals.

Arlecino [84]

545mm Hg in Kilopascals is 72.6607

I hope this helps you. Good luck stay safe, healthy and, happy!<3

6 0

2 years ago

When a substance is in the process of changing phases states of matter what happens to the temperature

Reptile [31]

Answer:

Temperature stays constant.

Explanation:

During a phase change, the temperature does not change. Temperature will only change when a phase change is completed.

8 0

2 years ago