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3 years ago

What is the atomic number and weight of Potassium?

Chemistry

1 answer:

il63 [147K]3 years ago

5 0

Answer:

Atomic Number: 19

Approximate Weight: 39.10 g/mol

Element: Alkali Metal

Explanation:

The Periodic Table of Elements gives these 3 information already.

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Need help ASAP DUE IN LIKE 2 minutes!!!!!!! Points are added

I am Lyosha [343]

Proton:

Positive

Found in Nucleus

Mass of 1 AMU

Neutron:

Neutral

Found in Nucleus

Mass of 1 AMU

Electron:

Negative

Found in orbitals

Mass of 0 AMU

Please mark Brainliest if this helped you! :)

7 0

2 years ago

What is the volume occupied by 4.20 miles of oxygen gas (O2) at STP

Drupady [299]

Answer: 94.13 L

Explanation: In STP in an ideal gas there is a standard value for both temperature and pressure. At STP,pressure is equal to 1atm and the temperature at 0°C is equal to 273.15K. This problem is an ideal gas so we use PV=nRT where R is a constant R= 0.08205 L.atm/mol.K.

To find volume, derive the equation, it becomes V=nRT/P. Substitute the values. V= 4.20 mol( 0.08205L.atm/mol.K)(273.15K) / 1 atm = 94.13 L. The mole units, atm and K will be cancelled out and L will be the remaining unit which is for volume.

8 0

2 years ago

A weak bond called a ______ bond results from an attraction between a slightly positive region in a molecule and a slightly nega

tamaranim1 [39]

Answer: The weak bond having slightly positive region and a slightly negative region is polar covalent bond.

Explanation:

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

They are of two types:

Polar covalent bond: This bond 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.

In this bond, a dipole is created. More electropnegative atom will have a slight negative charge and less electronegative atom will have a slight positive charge. For Example: $CO_2,NO_2$ etc..

Non-polar covalent bond: This bond 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..

Hence, the weak bond having slightly positive region and a slightly negative region is polar covalent bond.

7 0

2 years ago

ddt, dde, pcbs and pbdes are all ________ddt, dde, pcbs and pbdes are all ________.a biodegradable and do not persist in the env

qwelly [4]

The answer is non-biodegradable and subject to bioaccumulation and/or bioamplification.

DDT (dichlorodiphenyltrichloroethane) is persistent, non-degradable insecticide and organic pollutant readily accumulated to soils and consequently affects organisms.
DDE (dichlorodiphenyldichloroethylene) is non-degradable pesticide toxic to birds at the first place.
PCBs (polychlorinated biphenyls) are non-degradable organic compounds very toxic to the environment.
PBDEs (polybrominated diphenyl ethers) are non-degradable compounds very toxic to environment, even able to affect brains of animals in the development period.

5 0

3 years ago

Hydrogen peroxide can decompose to water and oxygen by the following reaction

mestny [16]

To begin calculating, there is one thing you need to remember : $1 mole of H2O2=34.0148 g$
Then we have $5.00g of H2O2=5/34.0148=0.146995$
As you know decomposition of 2moles now has prodused 196kj
So, q is made due $0.146995 moles of H2O2$ $=(-196/2)*0.146995=-14.40551Kj$
I'm sure it will help.

6 0

2 years ago