Answer:
Name, Thallium. Symbol, Tl. Atomic Number, 81. Atomic Mass, 204.3833 atomic mass units. Number of Protons, 81. Number of Neutrons, 123. Number of Electrons, 81 ... It has a metallic luster when it is first exposed to air but it tarnish quickly
Explanation:
Hope this helped :)
A car accelerates from 0 to 72 km/hour in 6.0 seconds. What is the car's acceleration?
The acceleration of the car is equal to 3.33 m/s² with a velocity of 72 Km/hr.
What is acceleration?Acceleration can be demonstrated as the rate of change of velocity over time. The acceleration can be explained as vector quantity due to both magnitude and direction. Acceleration is defined as the 2nd derivative of the position of the object w.r.t. time.
According to Newton's 2nd law of motion, the force exerted is equal to the mass times of acceleration of an object.
a = F/m
or, a = dv/dt
Given, the final velocity of the car, v = 72 Km/hr
v = 72 × 1000/3600 m/s
v = 20 m/s
The time is taken by car to travel, t = 20 s
The acceleration of the car, a = (20 - 0)/(6 - 0)
a = 3.33 m/s²
Therefore, the acceleration of the car is 3.33 m/s².
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The density of plutonium is 19.84 g/cm². What is its mass if the container has
volume of 250 cm?
Answer:
the answer is 7.936X 10⁻⁷kg.... the unit for volume must be cm³
Explanation:
we know,
ρ =m/v
given,
ρ =19.84/1000X(100)²= 1.984X10⁻⁶kg/m²
V (volume of the container means the volume of the element)=2.5 m³
NOW putting in the equation
1.984X10⁻⁶/2.5=m
or, m=7.936X 10⁻⁷kg(ANS)
thank u(i am not 100% sure but think it shoud be the answer)
STATE TRUE OR FALSE
a) natural gas has a characteristic odour
b) natural gas is heavier than air
c) synthetic fibres, polymers, dyes are synthesized from petrochemicals
d) we should use convential bulb's instead if LED'S
e) emission of CO2 gas during burning of fossil fuels burn global warming
which is the odd one out of clay pot , chalk , steel spoon and glass bowl(with explanation)
Answer:
chalk
Explanation:
most of them are utensils
A student lifts a bag from the floor to his or her shoulder 1.2m above the floor, using a force of 50N. How much work does the student do on the bag ?
60 J work does the student do on the bag.
The formula for work is as follows:-
[tex]W=F\times d[/tex]....(1)
Here, F is the force, and d is the distance moved in the direction of force.
Substitute 50 N for force and 1.2 m for distance in the equation (1) as follows:-
[tex]W=50\ N\times 1.2\ m\\\\=60\ Nm\\\\=60\ Joule[/tex]
Hence, the value of work is 60 J.
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What do you think happens to the matter in a food sample as it is burned?
Burning and other changes in matter do not destroy matter. The mass of matter is always the same before and after the changes occur. The law of conservation of mass states that matter cannot be created or destroyed
The thing that is happen in a food sample as it is burned is the chemical and physical change.
What is combustion reaction?Comubustion reactions are those reactions in which organic compound get burnt in the presence of oxygen for the formation of carbon dioxide gas and water molecule.
If the food sample contains the organic compound then it will convert into water and carbon dioxide gas and if it contains the matter in the form of inorganic compounds then it will convert into another product but having the same mass.
Hence if matter of food sample is burned then it will convert into small products as a result of physical or chemical change.
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Compare which element would have larger first ionization energy: an alkali metal in Period 2 or an alkali metal in Period 4?
AW: I think it would be alkali metal on period 2
Answer:
An alkali metal present in period 2 have larger first ionization energy.
Explanation:
Ionization energy:
The amount of energy required to remove the electron from the atom is called ionization energy.
Trend along period:
As we move from left to right across the periodic table the number of valance electrons in an atom increase. The atomic size tend to decrease in same period of periodic table because the electrons are added with in the same shell. When the electron are added, at the same time protons are also added in the nucleus. The positive charge is going to increase and this charge is greater in effect than the charge of electrons. This effect lead to the greater nuclear attraction. The electrons are pull towards the nucleus and valance shell get closer to the nucleus. As a result of this greater nuclear attraction atomic radius decreases and ionization energy increases because it is very difficult to remove the electron from atom and more energy is required.
Trend along group:
As we move down the group atomic radii increased with increase of atomic number. The addition of electron in next level cause the atomic radii to increased. The hold of nucleus on valance shell become weaker because of shielding of electrons thus size of atom increased.
As the size of atom increases the ionization energy from top to bottom also decreases because it becomes easier to remove the electron because of less nuclear attraction and as more electrons are added the outer electrons becomes more shielded and away from nucleus. Thus alkali metal present in period 2 have larger ionization energy because of more nuclear attraction as compared to the alkali metal present in period 4.
6.
Which best represents a particle containing 28 protons, 26 electrons, and 34 neutrons?
A Fe2-
B
54
2+
28N;
C%2Fe2-
DSNi2+
Answer:
Ni^2+
Explanation:
The following data were obtained from the question:
Proton = 28
Electron = 26
Neutron = 34
Next, we shall determine the atomic number of the element.
Atomic number of an element is simply defined as the number of protons in the atom of an element.
Thus,
Atomic number = proton number
Proton = 28
Atomic number = proton number = 28
Atomic number = 28
Therefore, the element is Nickel since no two elements have the same atomic number.
Finally, we shall determine the charge on the Nickel atom as follow:
Proton = 28
Electron = 26
Charge on atom =
Charge on atom = Proton – Electron
Charge on atom = 28 – 26
Charge on atom = +2
Therefore, we can represent the Particle as Ni^2+
What is the SI unit for mass
Answer:
kilo gram
Explanation:
kilogram(kg)
Answer:
Kilogram (Kg).......
What would be the charge of an ion with 9 protons, 10 neutrons, 10 electrons
Answer:
negative
Explanation:
Any atom whose number electrons are more than the number of protons in it will have a negative charge. Since in this case the electrons are 10 and protons are 9 the 9+ charge protons and 9- charge electrons cancel each other giving a final charge of negative.
The charge of an ion with 9 protons and 10 electrons and neutrons is -1 as there is one more electron in comparison to number of protons .
What is an ion?An ion is defined as an atom or a molecule which has a net electrical charge. There are 2 types of ions :1) cation 2) anion . The cation is the positively charged ion and anion is the negatively charged ion . As they are oppositely charged they attract each resulting in the formation of ionic bond.
Ions consisting of single atom are mono-atomic ions while which consists of two or more ions are called as poly-atomic ions . They are created by chemical interactions . They are very reactive in their gaseous state and rapidly react with oppositely charged ions resulting in neutral molecules.They are attracted to opposite charges.
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what is an oxidation reaction?
Fe + O2 —(H2O)—> Fe2O3
Which element has an atomic mass of 106.42?
Answer:
carbon
Explanation:
The element which has atomic mass of 106.42 is carbon as per the existing isotopes.
What is an element?
It is defined as a substance which cannot be broken down further into any other substance. Each element is made up of its own type of atom. Due to this reason all elements are different from one another.
Elements can be classified as metals and non-metals. Metals are shiny and conduct electricity and are all solids at room temperature except mercury. Non-metals do not conduct electricity and are mostly gases at room temperature except carbon and sulfur.
The number of protons in the nucleus is the defining property of an element and is related to the atomic number.All atoms with same atomic number are atoms of same element.
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What is the formula for Hydroxide
Answer:
OH-
Explanation:
it's consists of an oxygen and hydrogen atom held together by a covalent bond and carries a negative electric charge
Is this statement true or false? Why?
Chemical reactions are nothing more than rearrangements of protons.
Answer:
False. Answer in pic above
In fact protons have no role in chemical reactions. The regrouping of atoms itself forms the new products in chemical reactions. The reactions involves the loss/gain or sharing of electrons.
What is a chemical reaction ?A chemical reaction is a chemical change in which two or more atoms combine together to form a new product or a compound decomposes to form its constituent compounds. This involves breaking or making of bonds.
In a chemical reaction, no change occurs in the nuclear composition but the valence electrons are involved in the reaction. Atoms loss or gain electrons or share valence electrons with other atoms to form ne compounds.
The electrostatic force of attraction or the overlapping of atomic orbitals make the new products in a chemical reaction. Hence, the statement is false.
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The gold-foil experiment was used to discover which subatomic particle? Question 2 options: electrons protons ==> neutrons (my answer)
Answer:Proton, the gold foil experiment indicated that the nucleus has a positive charge.
HELP ASAP!! A pebble is dropped into a graduated cylinder and the volume rises from 25.0 mL to 31.0 mL. The mass of the pebble is 2.9g. What is the density of the pebble? (g/mL)
Answer:
The density of the pebble is 0.483g/mL (rounded), but it's 0.48333333333333 without rounding. Hope this helped! :)
Explanation:
Volume= 6.0mL Density=Mass/Volume
Mass= 2.9g
D=2.9g/6.0mL
D=0.48333333333333g/mL
or
D≈0.483g/mL
If the density of a gold coin is 19.3g/cm3, what would be the density of the coin if you cut it in half?
how many bonds are broken in 2O2
Answer:
c5mvmifvidvj8dvj9r kf9,g
How does a scientist test their hypothesis?
Answer:
Conducting experiments and using the scientific method.
Explanation:
Scientists (and other people) test hypotheses by conducting experiments. The purpose of an experiment is to determine whether observations of the real world agree with or conflict with the predictions derived from a hypothesis. If they agree, confidence in the hypothesis increases; otherwise, it decreases.
A different student is given a 10.0g sample labeled CaBr2 that may contain an inert (nonreacting) impurity. Identify a quantity from the results of laboratory analysis that the student could use to determine whether the sample was pure.
Answer:
Explanation:
It is density.
I do hope I helped you! :)
Look at the unbalanced reaction below for the combustion of hydrogen gas. What needs to be done to balance the reaction? _ H2 + _O2 LaTeX: \longrightarrow⟶ _H2O
Answer:
The given equation H2 + O2 => H2O is not balanced as the oxygen atom on the right side do not have the same number of atoms as of the left side.
In a balanced equation, the number of atoms on both sides are equal. So in this case, we are required to change the coefficient in front of H2O, in order to make oxygen atom balance, for that we need to change the coefficient of H2 as well.
It means to make the given equation balance we need to change the coefficient in front of H2 and H2O.
Balance equation: 2H2 + O2 => 2H2O
Laboratory equipment is cleaned and properly stored after use primarily so that
Options are provided in the given question, so the complete question is as follows:
Laboratory equipment is cleaned and properly stored after use primarily so that —
A. chemical products can be measured and recorded as data
B. time is saved in setting up the next experiment
C. toxic materials can be kept in the laboratory
D. the possibility of contamination in the laboratory is minimized
Answer:
D. the possibility of contamination in the laboratory is minimized
Explanation:
After the completion of experiments, all the laboratory equipment should be cleaned and properly stored to minimize the possibility of contamination in the laboratory.
Any contamination in the laboratory can affect the experiment and will not give an accurate result, so it is important to clean and store the equipment properly.
Hence, the correct answer is "D".
What is the difference between magma and lava?
Help PLZ!!!!!!
A Magma is molten rock within the earth; lava is molten rock on the earth's surface.
B Magma is cool, lava is very hot.
Magma is very hot, lava is cool,
Magma is molten rock on the earth's surface; lava is molten rock within the earth.
Answer:
the answer is A. Magma is molten rock within the earth; Lava is molten rock on the earth's surface
Answer:
A Magma is molten rock within the earth
Explanaton:
An ice cream company decides to make a new lower calorie flavor,but testers reported that the flavor wasnt as good as the original.Is this an example of trade off
Answer:
Yes, the given instance is an example of a trade-off.
Explanation:
The trade-off seems to be a strategy to minimize or surrender one or more favorable results in consideration for increasing either receiving other favorable results to optimize cumulative benefit or efficacy within such conditions.The above is indeed a trade-off since the participants are experimenting in exchange again for ice cream individuals have to enjoy. The ice cream manufacturer always gets a review of the technician in exchange for free ice cream.Calculate the destiny of the object that has a mass of 453 g and occupies the volume of 225 cm3
A ( 2.01g/cm3
B( 5.00 g/cm3
C( 453 g/cm3
D( 228 g/cm3
density = 2.013g/cm3
Explanation:
density = mass/volume
density = 453g/225cm3
density = 2.013g/cm3
How could contaminants from your community affect a river basin that is miles away?
contaminants from your community can flow through runoff into a river basin.
Contaminants from your community affect a river basin that is miles away could runoff can carry pollutants from your neighborhood into a river basin.
What is community?Community is defined as a social community that shares characteristics like geography, rules, beliefs, values, or identities. Community is important because they are frequently a significant source of social connection and a sense of belonging, strong communities are essential. Living a fulfilling life requires being a part of a group of people who share similar attitudes, values, and aspirations.
Contaminants are defined as a substance that, whether unintentionally or on purpose introduced to air, water, soil, or food, becomes detrimental to humans or other living things on a biological, chemical, physical, or radiological level. Chemical, physical, and biological pollution are the three different types.
Thus, contaminants from your community affect a river basin that is miles away could runoff can carry pollutants from your neighborhood into a river basin.
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Mr.Davies has requested that you wait for 10 more minutes is that informal or formal
Answer:
Formal
Explanation:
Answer:
I think its formal because the question looks a bit fancy by using all the present perfect tense..
hope this helped you
please mark as the brainliest ( if its correct)(ㆁωㆁ)
Which of the following example(s) from everyday life are made possible by modern chemistry?
If you could help me out I would really appreciate it. Thank you!
Answer:
I believe it is c
Explanation:
........................
From everyday life the following have been made possible by modern chemistry:
b. wearing a synthetic spandex athletic shirt
c. taking a pill to get relief from a cold
d. getting a boost of energy by eating an apple
Modern chemistry is a branch of chemistry that deals with the identification of structure, composition, physical as well as chemical properties of the substances that can help modern day humans to deal with their day to day problems like poor health, meeting energy requirements and others. Spandex is a material that has a chemical nature of absorbing the sweat from the body of athlete so this can be a part of modern chemistry. The chemical formulation of pill will help in fighting with the cold causing infecting agent in the body so it will help in overcoming the ill effects of cold thus helping mankind, so it is the part of modern chemistry. Apple is a source of sugar when it is metabolically broken in the body it releases energy which can be utilized by the body as a source of energy so it is a part of modern chemistry. Observing the sky at night during campaign is a physical phenomena.Hence, use of spandex in athletics shirt, pill for overcoming cold and apple as source of energy are parts of modern chemistry.
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4. m stands for....
a) millimeter
C) centimeter
b) meter
d) Liter
Answer:
meter
Explanation:
Which of the following is a single replacement reaction?
( a. Ba(OH)2 + H2SO4 → BaSO4 + 2H2O
( b. 2Mg + O2 → 2MgO
(c. H2O+ CO2 → H2CO3
(d. Zn + H2SO4 → ZnSO4 + H2
Answer:
D.
Explanation:
A. is double replacement. Ex. AX + BY -> AY + BX
B. is synthesis Ex. A + B -> AB
C. is synthesis
D. is Single replacement -> A + BX -> Ax + B
- Study definitions and examples of these and that will help.
When zinc react with sulfuric acid, then zinc sulphate is formed. Zn + H₂SO₄ → ZnSO₄ + H₂ this reaction is replacement reaction.
What is replacement reaction ?One element in a molecule is replaced by another in a chemical reaction known as a single-displacement reaction, sometimes referred to as a single replacement reaction or exchange reaction.
One element in a compound is switched out for another in a single replacement reaction. In a double-replacement process, the anions or cations of two ionic compounds are switched. In a double-replacement reaction known as a precipitation, a solid precipitate is one of the products.
One ingredient replaces another comparable element in a compound in a single-replacement reaction.
Thus, option D is correct.
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