rar please help?????????????????????????????????????????????????????

Density = mass ÷ volume  

           = 217.0 g ÷ 24.3 cm³  

           = 8.93 g/cm³

∴ the unknown sample of mass 217.0 grams and volume of 24.3 cm³ has a density of 8.93 g/cm³.

Answer:

Carbon is found in all living organisms.

Answer: d

Explanation: i promise I've took the k-12 test

Explanation:

Atoms are at their most stable when their outermost energy level is either empty of electrons or filled with electrons. Sodium atoms have 11 electrons. Two of these are in the lowest energy level, eight are in the second energy level and then one electron is in the third energy level.

Any atom is most stable when it’s outermost energy level contains eight electrons.

An atom is defined as the smallest unit of matter which forms an element. Every form of matter whether solid,liquid , gas consists of atoms . Each atom has a nucleus which is composed of protons and neutrons and shells in which the electrons revolve.

The protons are positively charged and neutrons are neutral and hence the nucleus is positively charged. The electrons which revolve around the nucleus are negatively charged and hence the atom as a whole is neutral and stable due to presence of oppositely charged particles.

Atoms of the same element are similar as they have number of sub- atomic particles which on combination do not alter the chemical properties of the substances.

Learn more about atom,here:

https://brainly.com/question/13981855

#SPJ6

Explanation: The additional terminology comes from the definition that, within redox processes, a reductant transfers electrons to an oxidant; hence, the reductant (reducing agent) loses electrons, so is oxidized, while the oxidant (oxidizing agent) gains electrons, so is reduced.

In an oxidation-reduction reaction, the reducing agent loses electrons and loses potential energy, Therefore, option (C) is correct.

A substance that loses its electrons in a redox reaction to other substances and gets oxidized is called a reducing agent. A reducing agent is one of the reactants which reduces the other reactant by donating the electrons to the reactant of an oxidation-reduction reaction.

If the reducing agent can't pass electrons to another reactant in a reaction, then the reduction process does not occur and the reaction cannot proceed.

In redox reactions, when an electron loses potential energy as a result of the transfer and energy is released. Electrons with more potential energy are associated with less electronegative atoms and less potential energy is associated with a more electronegative atom (such as O).

Therefore, the reducing agent loses electrons and loses potential energy in a redox reaction.

Learn more about reducing agent, here:

https://brainly.com/question/15584308

#SPJ2

Your question is incomplete, but probably the complete question was,

In an oxidation-reduction reaction, how is the reducing agent changed?

(A) it gains electrons and gains potential energy

B) it gains electrons and loses potential energy

C) it loses electrons and loses potential energy

D) it loses electrons and gains potential energy

the correct one is D

Answer:

First one answer is physical and other remaning chemical

Answer:

Hydrogen is a colorless, tasteless, and odorless gas.  

physical

--------------------------------------------------------------------------------------------------------------

Hydrogen is very combustible in the presence of oxygen.  

chemical

--------------------------------------------------------------------------------------------------------------

Hydrogen is very reactive with most elements.  

chemical

--------------------------------------------------------------------------------------------------------------

Hydrogen is the least dense of all elements.  

physical

Answer:

a molecule is a group of atoms/elements bonded together

Answer:

 A FLUORINE

Explanation:

Explanation:

Option A, Fluorine is the correct answer, because it has 9 electrons in its shells.

hope this helps you.

Answer:

it is matter cus everything is made up of matter

Explanation:

Answer: yes

Explanation:

Matter makes up everything

Answer: Luster: Metals are shiny when cut, scratched, or polished.

Malleability: Metals are strong but malleable, which means that they can be easily bent or shaped.

Conductivity: Metals are excellent conductors of electricity and heat.

Explanation: Hope this helped!

Answer:

D) C2H6

Explanation:

All the other molecules contain double (or triple) bonds except for C2H6.

Answer:

Explanation:

1. Virus's are hard to detect because of their simple construction.

2. Some mutate very easily.

3. It is hard to isolate the virus and kill it without doing damage to the host.

Answer:

human migration

Explanation:

Answer:

I think its D

Explanation:

Answer:

Option C

Explanation:

Its totally chemical change

Answer:

E- an ion is positive if it has more protons than it has neutrons

Answer:

ionic

Explanation:

ionic transfer of e^- ions formed (charges)

ionic=non-metal+ metal

ex: F+Ca

covalent sharing e^- no true charges

covalent= non-metal+ non-metal

ex: F+P

( my notes)

Answer:

24 hours

Explanation:

There are 24 hours in a day cause that is how long for the earth to spin on its axis

Answer:

24 hours

Explanation:

The time it takes Earth to rotate so the sun appears in the same position in the sky, known as a solar day, is 24 hours. However, the time it takes Earth to complete one full rotation on its axis with respect to distant stars is actually 23 hours 56 minutes 4.091 seconds, known as a sidereal day.

Answer:

(n, l, m sub l, m sub s)

N: principle quantum number (1,2,3,4,etc)

l: angular momentum quantum number, the shape (l has to be at least 1 less than n, but can be 0 depending on n)

M sub l: magnetic quantum number (l determines this number)

M sub s: spin quantum number (can only ever be 1/2 or -1/2)

Explanation:

The principle, azimuthal, magnetic, and spin quantum numbers specify the principle shell, the shape of the orbital, the number of orbitals, and electron spin respectively.

The set of numbers that describes the position and energy of the electron are called quantum numbers. Four quantum numbers are principal, azimuthal, magnetic, and spin quantum numbers.

Principal quantum numbers (n) designate the principal electron shell of the atom and the most probable distance between the nucleus and the electrons. A larger value of the principal quantum number indicates a large distance between the electron and the nucleus.

The azimuthal quantum number (l) describes the shape of an orbital in which an electron is present. Its value is equal to the total number of angular nodes in that orbital.

The magnetic quantum number describes the total number of orbitals in a subshell and the orientation of these orbitals.  The value of the spin quantum number (s) offers the direction in which the electron is spinning and it has only two possible values +½ and -½.

Learn more about quantum numbers, here:

https://brainly.com/question/16977590

#SPJ2

Hope you could get an idea from here.

Doubt clarification - use comment section.

Answer:

c. chlorine, with an outer electron shell filled with 7 of a possible 8 electrons

Explanation:

Hope this helps!

The structure in the option A has 7 electrons in the outer shell of its electronic configuration , is unstable and so is most likely to form bond with another atom.

Electrons are arranged in various shells around the nucleus , this arrangement is called electronic structure or configuration.

Each shell can occupy certain fixed number of electrons.

Beside Option A , all the other configurations show stable structures as the last shell has eight electrons and are stable according to the octet rule.

The structure in the option A has 7 electrons in the shell and so is most likely to form bond with another atom.

To know more about Electronic Configuration

https://brainly.com/question/26084288

#SPJ2

Answer:

By using various chemical compounds to lift the stain while being gentle enough to keep fabric intact.

Answer:

Temperature and pressure are the two factors which are responsible for change in state of matter.

Solid – In a solid, the attractive forces keep the particles together tightly enough so that the particles do not move past each other. ... In the solid the particles vibrate in place. Liquid – In a liquid, particles will flow or glide over one another, but stay toward the bottom of the container.

Hope this helps, mark as Brainliest please...

Answer:

Saponification

Explanation:

When treated with a base such as NaOH, the ester is transformed back to alcohol and the sodium salt of carboxylic acid. Saponification is the name given to the reaction since it is utilized in the production of soap.

Answer:

Sorry pal! Didn't understand your language.  

:(

Explanation:

Answer:

The specific heat of water is 4.18 J/g C.

Explanation:

q

=

m

C

s

Δ

T

Never forget that!

2200

=

m

⋅

4.18

J

g

⋅

°

C

⋅

66

°

C

∴

m

≈

8.0

g

Explanation:

lithium has group 1 elements and it valance electron has 1

so it more react with group 7 to be more stable

Answer:

protons and neutrons

Explanation:

Neutrons and protons are the particles that are found in the nucleus of an atom.

Protons and neutrons are subatomic particles. They are present in the nucleus of an atom and constitute most of the mass of the atom. There are three kinds of subatomic particles that are present in an atom.

These are -

Since most of the mass of the atom, in the form of protons and neutrons, is present in the nucleus, the mass number is denoted as the sum of the number of protons and neutrons. Protons and neutrons together are sometimes also called nucleons.

Therefore, neutrons and protons are present in the nucleus of an atom.

Read more about subatomic particles, here

https://brainly.com/question/13303285

#SPJ2