Answer:
Today, I will present the first eighteen elements which are Hydrogen, Helium, Lithium, Beryllium, Boron, Carbon, Nitrogen, Oxygen, Fluorine, Neon, Sodium, Magnesium, Aluminum, Silicon, Phosphorus, Sulfur, Chlorine, and Argon.
First 5: Hydrogen. The first and simplest element on the periodic table.
Helium. a very light colorless element that is one of the six inert gasses.
Lithium. A very soft, light metal.
Beryllium. A very light metal; although it is 3 1/2 times the density of Lithium.
Boron. The fifth element in the periodic table.
Explanation:
In chemistry class, Allen determined the effectiveness of various metals in releasing hydrogen gas from hydrochloric acid. Several weeks later, Allen read that a utilities company was burying lead next to iron pipes to prevent rusting. Allen hypothesized that less rusting would occur with the more active metals. He placed the following into 4 separate beakers of water: (a) 1 iron nail, (b) 1 iron nail wrapped with an aluminum strip, (c) 1 iron nail wrapped with a magnesium strip, and (d) 1 iron nail wrapped with a lead strip. He used the same amount of water, equal amounts (mass) of the metals, and the same type of iron nails. At the end of 5 days, he rated the amount of rusting as small, moderate, or large. He also recorded the color of the water. What is the independent variable?
a) the amount of water
b) the metals strips
c) amount of rust
d) hydrochloric acid
Answer:
b) the metals strips
Explanation:
In an experimental design, an independent variable is a variable that is changed or manipulated in a series of experiments. An independent variable is not dependent on any other variable in the experiment. The hypothesis for this experiment is stated to be: "If the chemical activity of the metallic wrapper is increased, then less rusting of iron will occur. The independent variable relates to the type of metal wrapping strip, and the dependent variables are the amount of rusting and color of the water.
In 25 words or fewer, what do you think a scientist would want to explain about this soda?
Answer:
This soda is brown, sweet, has high carbonation, and is about 200 calories when consumed.
Explanation:
:)
Also can someone help me with this one as well, thank you! :)
Answer:
a. The density of the aluminum will change if the sample gets too big.
Explanation:
Since increasing its size increases its volume hence it affects the value of its density by decreasing.
note: Density = mass/volume.
What type of radioactive decay is shown? 82 Br → 82 Kr + te 35 36 Alpha O Beta O Gamma?
Answer:
In 1889, Ernest Rutherford recognized and named two modes of radioactive decay, showing the occurrence of both processes in a decaying sample of natural uranium and its daughters. Rutherford named these types of radiation based on their penetrating power: heavier alpha and lighter beta radiation. Gamma rays, a third type of radiation, were discovered by P. Villard in 1900 but weren't recognized as electromagnetic radiation until 1914. Since gamma radiation is only the discharge of a high-energy photon from an over-excited nucleus, it does not change the identity of the atom from which it originates and therefore will not be discussed in depth here.
Because nuclear reactions involve the breaking of very powerful intra nuclear bonds, massive amounts of energy can be released. At such high energy levels, the matter can be converted directly to energy according to Einstein's famous Mass-Energy relationship E = mc2. The sum of mass and energy are conserved in nuclear decay. The free energy of any spontaneous reaction must be negative according to thermodynamics (ΔG < 0), and ΔG is essentially equal to the energy change ΔE of nuclear reactions because ΔE is so massive.
Explanation:
Hope it helps
Easy Chemistry/ Help
Relate pH values of 9.1, 1.2, and 5.7 to hydronium and hydroxyl ion concentration.
Answer:
9.1 = basic 1.2= very acidic 5.7= acidic
Explanation:
What are the first two levels of cellular organization?
Answer:
Cells and tissue
Explanation:
Cells are the smallest functional units of all living things
Tissue is organic material from which organs and their bodily structures appear
write the cations and anions present in NaCl
What is the number of protons for the following?
190
+2
Os
76
Answer:
190+2=192
Explanation:
192 add it 192 added
Answer: they are right
Explanation:
Please can anyone help me? How are the first 20 elements of the periodic table constructed?
Answer:
Based on the periodic law
Explanation:
All the elements on the periodic table were constructed based on the periodic law.
Henry Moseley in the 1900s re-stated the periodic law by changing the basis of the law from atomic weight to atomic number. The present periodic law is therefore "the properties of elements are a periodic function of their atomic number".
The atomic number is the number of protons in an atom. Based on the graduation of atomic number on the periodic table, elements are classified into groups and periods.Two individual atoms of the same element are slightly different. One has one more proton than it has electrons. The other has one more electron than it has protons. These atoms are both
ions
isotopes
freons
xenons
phlogistons
Answer:
ions
Explanation:
Individual atoms of the same element but having slightly different number of protons and electrons are called ions.
Ion is a charged particle.
An atom is made up of three fundamental subatomic particles. Protons are the positively charged particles Electrons are the negatively charged particles Neutrons do not carry any charges.When the number of protons > electrons the body is positively charged.
When the number of electrons > protons the body is negatively charged.
Charged particles are called ions.
How many atoms of nitrogen are in the chemical formula Ni(NO3)2?
Answer:
2
Explanation:
bc the 2 that's after a bracket refers to both oxygen and nitrogen, making oxygen 6 bc it already has a 3(3×2=6)
Answer:
2
Explanation:
can you guys help me
Answer:
B) 6 Newtons
Explanation:
Applied Force = 10 N
Resistive Frictional Force = 4 N
As we know that frictional forces always act in the opposite of the relative motion [force], and that opposite forces always subtract.
Hence,
The Net Force acting on the block = 10 N -4 N = 6 Newtons
Answer: The Answer is B
PLEASE HELP I'LL MARK BRAINLIEST
Describe, on the molecular level, why my glasses get fogged up when I wear my face mask (so dang annoying). Be sure to use these terms: -decreased kinetic energy -surface -attraction
Answer:
When you are in a cool place and exhale into your mask, the mask blocks and re-directs some of your breath up toward the top edge of the mask and under your glasses. ... When the warm breath hits the cool lens, the water in the breath condenses causing your lenses to fog up.
At 303 K, the volume of a gas is 30.0 ml. At constant pressure, what is the new
volume of the gas if the temperature is decreased to 283K?
Answer:
V₂ = 28 mL
Explanation:
Given data:
Initial temperature = 303 K
Initial volume = 30.0 mL
Final temperature = 283 K
Final volume = ?
Solution:
The given problem will be solve through the Charles Law.
According to this law, The volume of given amount of a gas is directly proportional to its temperature at constant number of moles and pressure.
Mathematical expression:
V₁/T₁ = V₂/T₂
V₁ = Initial volume
T₁ = Initial temperature
V₂ = Final volume
T₂ = Final temperature
Now we will put the values in formula.
V₁/T₁ = V₂/T₂
V₂ = V₁T₂/T₁
V₂ = 30.0 mL × 283 K /303 K
V₂ = 8490 mL.K / 303 K
V₂ = 28 mL
yo, i need help. 25 points and brainliest. :|
Answer:
here's your answer...
Explanation:
Full moon, also hey lol.
have a germ-free day.
The force of attraction between one polar molecule and another polar molecule is
Answer:
Dipole-dipole forces
Explanation:
A polar compound is that compound which contains atoms that have a difference in charges i.e electrostatic attraction occurs between its constituent atoms. Polar molecules are attracted to other polar molecules with opposite charges and her held together with the aid of certain forces
The attractive force between the negative part of a polar molecule (-) and the positive part of another polar molecule (+) is called DIPOLE-DIPOLE FORCES. This dipole-dipole force gets stronger with an increasing polarity of the molecules involved.
What is the mass 5.00 x 1022 molecules of PbCI2
Answer:
ion know this one
Explanation:
Plants make their own food and are not required to consume food for energy. Into which category does this characteristic cause plants to be assigned?
Answer:
Autotrophic or Producers
Explanation:
They are often called producers because they make their own food.
property of an acide
Answer:
hi
Explanation:
acids are corrosive, rective when combined with bases form salt and when combined with metal form h2o
Answer:
page no,165 ma xa. yo question KO ans
Which of the following diagrams correctly represents the formation of a compound consisting of magnesium and fluorine?
Answer:
See explanation
Explanation:
The image attached describes the formation of magnesium fluoride.
Magnesium has two valence electrons while fluorine has seven valence electrons. Magnesium can now transfer one electron each to two fluorine atoms thereby forming the compound MgF2.
This has been shown pictorially in the image attached to this answer.
Write the net ionic equation for the following reaction:
AgC2H3O2(aq) + CaCl2(aq) →
Answer:
2Ag^+(aq) + 2Cl^-(aq) --------> 2AgCl(s)
Explanation:
The net ionic equation reflects the main reaction that occurred in the system. It tells you the most important reaction that took place.
If we first put down the balanced molecular equation for the reaction, we have;
CaCl2(aq) + 2 AgC2H3O2(aq) ---------> 2 AgCl(s) + Ca(C2H3O2)2 (aq)
The net ionic equation is;
2Ag^+(aq) + 2Cl^-(aq) --------> 2AgCl(s)
BRAINLEST WILL BE GIVEN TO A RIGHT ANSWER!!!!
Potassium (K) has a charge of +1, and sulfur has a charge of –2. Which best describes the compound they make?
A) The chemical formula is K2S, and the name is potassium sulfide.
B) The chemical formula is KS2, and the name is potassium sulfide.
C) The chemical formula is K2S, and the name is sulfur potassium.
D) The chemical formula is KS2, and the name is sulfur potassium.
Answer:
A) The chemical formula is K2S, and the name is potassium sulfide. Explanation:
edge
why carbon is a basic thing to classify as organic and inorganic compounds?
Answer:
To answer, all living organisms contain carbon-based compounds, which classifies them organic.
Simply, carbon dioxide, is an example of an inorganic compound since it does not contain both carbon and hydrogen. Alternatively, one molecule of carbon dioxide contains one atom of carbon and two atoms of oxygen.
How many liters of ammonia are formed with 49.8 g of nitrogen gas reacting with 10.7 g of hydrogen gas at S.T.P.?
Why are liquid and gas molecules different
Lily replicates an experiment that found that the number of calories in a particular food is 50 kcal. She obtained data from five trials: 50 kcal, 72 kcal, 50 kcal, 12 kcal, and 50 kcal.
Which best describes her data results?
accurate
incorrect
invalid
precise
PLEASE HURRY IM TIMED
Answer:
the best that describes her data result is precise
Which element wants to gain valence electrons while bonding?
a. Neon (Ne)
b. Fluorine (FI)
c. Lithium (Li)
d. Magnesium (Mg)
Answer:
b. Fluorine (FI)
Explanation:
From the given choices, only fluorine wants to gain valence electrons while bonding.
This is because fluorine is the most electronegative specie from the given choices. An electronegative substance have a high tendency to attract electrons to itself in a bond.
Neon is a noble gas and it is stable. Lithium and Magnesium are metals that are electropositive. They prefer to lose electrons than to gain electrons.A metal atom and a non-metal atom bond together. What type of bond do they form?
Question 8 options:
Ionic
Round
Covalent
Glue
Answer: Iconic
Explanation:Ionic bonds are formed through the exchange of valence electrons between atoms, typically a metal and a nonmetal.
what is the name of this atom?
A.) Beryllium
B.) Boron
C.) Fluorine
D.) Helium
Answer:
Explanation:
A .