Answer: Positive- Protons
Negative- Electrons
Explanation:
Why can’t a smartphone disappear completely in liquid acid?
Answer:
its metal because its metal
1. Which statement describes the earliest model of
the atom?
Answer:
A). An atom is an indivisible hard-sphere.
Explanation:
The 'Atomic Theory' of Dalton is characterized as the earliest model(came in 1803) which described the atoms as the indivisible and resistant spheres. He used the example of watermelon to elaborate that the atoms of a specific element share similar characteristics and the atoms of distinct elements differ in their mass as well as their size. Thus, option A is the correct answer.
.
please help It's due today please
Answer:
i have no clue
Explanation:
Answer:
??????????
Explanation:
acronyms for the first 20 elements
Answer:
HHeLiBeBCNOFNeNaMgAlSiPSClArKCaAnswer:
Acronym Elements Symbols
He Hydrogen H
has Helium He
light Lithium Li
brain Beryllium Be
but Boron B
can Carbon C
not Nitrogen N
offer Oxygen O
full Fluorine Fl
nine Neon Ne
subjects Sodium Na
must Magnesium Mg
all Aluminium Al
silly Silicon Si
people Phosphorus P
stop Sulphur S
calling Chlorine Cl
a Argon Ar
pope Potassium K
christ Calcium Ca
what is the atomic number of carbon
What is the force of gravity between the earth and the mass of 1kg placed on its surface? (Mass of earth = 6 x 10^24 kg)
Given that,
Mass, m = 1 kg
Mass of the Earth, [tex]M=6\times 10^{24}\ kg[/tex]
Radius of Earth, r = 6378 km
To find,
The gravitational force.
Solution,
The formula for the gravitational force is given by :
[tex]F=\dfrac{GmM}{r^2}\\\\F=\dfrac{6.67\times 10^{-11}\times 1\times 6\times 10^{24}}{(6378 \times 10^3)^2}\\\\F=9.83\ N[/tex]
So, the required force is 9.83 N.
Monsters are real, and ghosts are real too. They live inside us, and sometimes, they win - Stephen King.
━━━━━━━━━━━━━
Answer:
so what is the question?
where is the question?
thank you for free points. GBU.
what is the total number of atoms in a molecule of the compound li2so4
Answer:
Explanation:
Element Symbol Atomic Mass # of Atoms Mass Percent
Lithium Li 6.941 2 12.626%
Oxygen O 15.9994 4 58.209%
Sulfur S 32.065 1 29.165%
Caffeine has the molecular formula, C8H10N4O2. What is the percent composition of caffeine?
Select one:
a) 33.33% C, 41.67% H, 16.67% N, and 8.33% O
b) 49.48% C, 5.19% H, 28.85% N, and 16.48% O
c) 25% C, 25% H, 25% N, 25% N, and 25% O
d) 27.92% C, 2.34% H, 32.56% N, and 37.19% O
Answer:
b) 49.48% C, 5.19% H, 28.85% N, and 16.48% O
Explanation:
we find the mass for each element in one mole by multiplying the number of atoms in one molecule with the atomic mass
mC=8Ac=8*12=96g
mH=10AH=10*1=10g
mN=4AN=4*14=56g
mO=2AO=2*16=32g
by adding the masses together we find the molar mass of the molecule
M=mC+nH+mN+mO=96+10+56+32=194g/mole
we apply the rule of threes to find the percentage of each element
194g..96gC..10gH...56gN....32gO
100g....a...........b...........c.............d
a=(100*96)/194=49.48%C
b=(100*10)/194=5.19%H
c=(100*56)/194=28.85%N
d=(100*32)/194=16.48%O
Which of the 3 sub particles of an atom, weighs the LEAST?
Hydrogen and oxygen combine in the ratio of 1:8 by mass to form water. How many grams of hydrogen are needed to react completely with 6.4 g of oxygen gas? Show complete working. Which law of chemical combination will govern your answer? Write the law.
Explanation: Number of moles of water = mass of water/ molar mass.
Molar mass of H2O = (1*2) + 16 = 18.0
Now we only need to calculate the number of moles of water.
The chemical reaction is as follows
CH4 + 2O2 ---> CO2 + 2H2O
From the eqn, the moles of H2O = 2*moles of CH4
Molar mass of CH4 = 12 + 4 = 16. Number of moles of methane = mass/
molar mass. No of moles = 6.4/16 = 0.4. So the number of mole of water = 2* 0.4 = 0.8. We already calculate its molar mass earlier. So mass of water = molar mass * number of moles = 18 * 0.8 = 14.4
bohr's work demonstrate the importance of communication in science because it wouldn't have been possible without the work of other scientists.
true or false
Answer:
Why science communication is important? In the world we live in, not only does pursuing science matter but communicating about it effectively is important as well. Communicating about science is crucial, whether we communicate about it online or face to face, communication about the scientific facts is vital for the scientific community. This is especially important now when many question scientific methods, research, and results. We are not only talking about communication about science between academics, scientists and corporations, but we are also talking about the gap between the scientific world and non-scientific community.
true
The given statement is true.
• The atomic model of Bohr was based on the model given by Rutherford as he clarified the location of electrons.
• Based on Bohr's model, the electrons only at the fixed distances from the nucleus orbit around it known as the energy levels.
• The work of Bohr illustrates the significance of communication in science as it would not be possible without the contribution of other scientists.
• The atomic model of Bohr was built upon the atomic models of other scientists, mainly Rutherford.
Thus, the given statement is true.
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In the pie chart below, which of the following represents the amount of Earth's water located in the oceans?
A pie chart with part A representing 2%, part B representing .8%, part C representing .2% and part D representing 97%.
© 2011 FLVS
A only
A and B
C only
D only
Answer:
D. 97%
Explanation:
♪＼(*＾▽＾*)／＼(*＾▽＾*)／
Answer:
d
Explanation:
What are the 3 reactants necessary for photosynthesis
Answer:
Carbon dioxide
Water
Glucose
Answer:
To perform photosynthesis, we need three things: Carbon Dioxide WaterSunlightdescribe how vitamin A may be used in the body
Answer:
Vitamin A is important for normal vision, the immune system, and reproduction. Vitamin A also helps the heart, lungs, kidneys, and other organs work properly. There are two different types of vitamin A. The first type, preformed vitamin A, is found in meat, poultry, fish, and dairy products.
Answer:
Vitamin A helps form and maintain healthy teeth, skeletal and soft tissue, mucus membranes, and skin. It is also known as retinol because it produces the pigments in the retina of the eye. Vitamin A promotes good eyesight, especially in low light. It also has a role in healthy pregnancy and breastfeeding.
:-))
How many moles are in 3.57 x 10 32
particles Ca?
Answer:
[tex]\boxed {\boxed {\sf 592,826,303.6 \ moles \ of \ Ca }}[/tex]
Explanation:
To convert from moles to particles, we must Avogadro's Number.
[tex]6.022*10^{23}[/tex]
This number tells us the number of particles (atoms, ions, molecules, etc.) in 1 mole of a substance. In this case, it is the particles of calcium in 1 mole of calcium.
[tex]6.022*10^{23} \ particles \ Ca / mole \ Ca[/tex]
We can use Avogadro's Number as a ratio or fraction.
[tex]\frac{6.022 *10^{23} \ particles \ Ca}{1 \ mol \ Ca}[/tex]
Multiply this by the given number of particles (3.57*10³²).
[tex]3.57*10^{32} \ particles \ Ca*\frac{6.022 *10^{23} \ particles \ Ca}{1 \ mol \ Ca}[/tex]
Flip the fraction so the particles of calcium will cancel out.
[tex]3.57*10^{32} \ particles \ Ca*\frac{1 \ mol \ Ca}{6.022 *10^{23} \ particles \ Ca}[/tex]
[tex]3.57*10^{32} *\frac{1 \ mol \ Ca}{6.022 *10^{23} }[/tex]
[tex]\frac{3.57*10^{32} \ mol \ Ca}{6.022 *10^{23} }[/tex]
[tex]592826303.6 \ mol \ Ca[/tex]
There are 592,826,303.6 moles of calcium in 3.57*10³² particles of calcium.
Which of the following statements is true?
A.
Protons are located outside the nucleus of an atom.
B.
Electrons do not have mass.
C.
Individual atoms can be seen with the naked eye.
D.
The nucleus of an atom contains protons and neutrons.
Reset
Answer:
Option D
Explanation:
The nucleus of an atom consists of both protons and neutrons
Answer:
d
Explanation:
the nucleus of an atom contains protons and neutrons.
Look at the simplified Periodic Table in the attachment. Each letter
represents an element but the letter is not the real chemical symbol.
Use your knowledge to sort the letters to say whether they are metal
or non-metal elements.
W
Y
V
Z
x
Answer:
According to this picture w and y are metals and v z and x are non metals
Explanation:
The pH is given for three solutions. Calculate (H+] and [OH-] in each solution.
b. pH = 11.05
Plss show work
How many Valence electrons and energy shells does Ge have?
A.4 Valence Electrons and 6 Energy shells
B.7 Valence Electrons and 3 Energy shells
C.2 Valence Electrons and 6 Energy shells
D.4 Valence Electrons and 4 Energy shells
Answer:
D. 4 Valence Electrons and 4 Energy shells
Explanation:
Hello!
In this case, since finding the number of valence electrons and energy shells require the determination of the electron configuration for the element, knowing that germanium has 32 electrons (atomic number), we have:
[tex]1s^2,2s^2,2p^6,3s^2,3p^6,4s^2,3d^{10},4p^2[/tex]
We can see that the outermost energy shell is 4 which storages 4 electrons (2 from 4s and 2 from 4p); therefore, we infer it has 4 valence electrons and 5 energy shells, so the answer is:
D. 4 Valence Electrons and 4 Energy shells.
Best regards!
In a percentage composition investigation a compound was decomposed into its elements: 20.0 g of calcium, 6.0 g of carbon, and 24.0 g of oxygen. Determine the percentage composition of this compound
The percentage composition of this compound : 40%Ca, 12%C and 48%O
Further explanationGiven
20.0 g of calcium,
6.0 g of carbon,
and 24.0 g of oxygen.
Required
The percentage composition
Solution
Total mass of compound :
=mass calcium + mass carbon + mass oxygen
=20 g + 6 g + 24 g
=50 g
Percentage composition :
Ca-calcium[tex]\tt \dfrac{20}{50}\times 100\%=40\%[/tex]
C-carbon[tex]\tt \dfrac{6}{50}\times 100\%=12\%[/tex]
O-oxygen[tex]\tt \dfrac{24}{50}\times 100\%=48\%[/tex]
Plz I need help with my chemistry homework jJnsjs
answer
1.1 Carbon is the sixth element in the periodic table.
(IV A)
1.2 electric configuration: O⁸ (He²) 2s² 2p⁴ .
atomic number: 8
1.3 protons= 8 , electron = 7
1.4 oxygen has 6 valence electrons .
carbon has 4 valence electrons.
1.5 the answer is in the photo.
1 How many moles of solute are in:
a 500 cm of solution, of concentration 2 moldm"?
b 2 litres of solution, of concentration 0.5 mol/dm?
Pls answer I will mark the person brainliest
Moles of solute for both a and b are the same = 1 mol
Further explanationGiven
a 500 cm³ of solution, of concentration 2 mol/dm³
b 2 litres of solution, of concentration 0.5 mol/dm³
Required
moles of solute
Solution
Molarity shows the number of moles of solute in every 1 liter of solution or mmol in each ml of solution
Can be formulated :
[tex]\large \boxed {\bold {M ~ = ~ \dfrac {n} {V}}}[/tex]
a.
V = 500 cm³ = 0.5 L
M = 2 mol/L
n=moles = M x V
n = 2 mol/L x 0.5 L
n = 1 mol
b.
V = 2 L
M = 0.5 mol/L
n=moles = M x V
n = 0.5 mol/L x 2 L
n = 1 mol
What is the difference between weight and mass?
Answer: it's easy just think about it:
Explanation:
weight: the weight of an object is the force acting on the object due to gravity.
mass: Mass is the amount of matter or substance that makes up an object.
in total: The mass of an object is a measure of the object's inertial property, or the amount of matter it contains. The weight of an object is a measure of the force exerted on the object by gravity, or the force needed to support it.
Happy to help!
Feel free to ask any questions!
answer: mass is the amount of matter in a material(m)
and weight is a measure of how the force of gravity acts upon that mass(m*g)
How many half-lives took place if I started with 125,000 atoms, and I now only
have 15,625 of the original atom?
what is electrochemistry?
A. the study of photons in chemistry
B. the study of electricity in chemistry
C. the study of charge particles in chemistry
D. the study of valence-electrons in chemistry
Answer:
B. the study of electricity in chemistry
Explanation:
Electrochemistry is the study of chemical processes that cause electrons to move. This movement of electrons is called electricity, which can be generated by movements of electrons from one element to another in a reaction known as an oxidation-reduction ("redox") reaction.
Answer:
B => Study of electricity in chemistry
Explanation:
Electrochemistry is the study of electricity associated with chemical oxidation-reduction reaction. It is divided into two distinct disciplines; electrolysis and Galvanic Process.
Electrolysis is a nonspontaneous process requiring an outside power source (typically a battery) to drive the chemical reactions. Applications include metal refining and generation of various gases (for collection) by chemical process.
Galvanic Process is a spontaneous chemical process generating electrical energy by taking advantage of the different properties of metals. Applications include batteries for many devices such as flash lights (Leclanche dry cell), alkaline button batteries for hearing aids, automobile batteries (lead storage batteries), the H₂/O₂ Fuel Cell battery, etc.
In general,
Electrolysis => Uses electrical energy (batteries) to drive chemical reactions
or,
Galvanic Process => Using chemical reactions to generate electrical energy
These are the last two questions on the sheet I need help with haha, help only the ones you can! (most helpful answer will get brainliest)
Answer:
the 7 question answer is c the 24 question answer is b
Explanation:
Which of the following industrial processes involves a voltaic cell rather than electrolysis?
coating forks and knives with silver ?
extracting sodium from sodium hydroxide ?
reinforcing the hull of a ship so that it resists corrosion ?
converting energy stored in chemical bonds to electricity ?
Answer: D. Converting energy stored in chemical bonds into electricity.
Explanation:
100% on edg 2021 quiz.
Answer:
D. converting energy stored in chemical bonds to electricity
Explanation:
Edge 2020
Identify the variables in the investigation: An investigation was done with an electromagnetic system made from a battery and wire wrapped around a nail. Different size nails were used. The number of paper clips the electromagnet could pick up was measured.
Answer:
Independent: sizes of nails
Dependent: number of paper clips
Controlled: Battery, wire and type of nails
Explanation:
An independent variable is a variable which when changes does not the effect the results of the experiment. It does not depends upon the dependent variable.
A dependent variable is defined as a variable which is affected when the independent variable is changed by the researcher or the experimenter. It depends greatly upon the independent variable.
While a controlled variable is that variable whose value is not changed in an experiment. It contains all the constants.
In the context,
the independent variable are : sizes of nails
the dependent variables are : number of paper clips
the Controlled variables are: Battery, wire and type of nails
What is misleading about the terms “melting point” and “boiling point”?
Answer:
The melting point is when a solid is turning into a liquid, boiling point is when a liquid turns into a gas. The thing that is misleading is that they are both changing state because of heat.
Explanation:
When a solid melts into a liquid, the melting point has been reached, and when a liquid changes into a gas, the boiling point is reached.
Melting point and Boiling point:The melting point is defined as the temperature at which solid and liquid phases are in equilibrium, whereas the boiling point is defined as the temperature at which a liquid's vapor pressure equals the external pressure.
What's confusing is that they're both changing states as a result of heat.
Find out more information about 'Melting point'.
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