Which of the following is an example of very early scientific research?
sleeping in caves to avoid predation by animals
painting pictures and symbols on cave walls
making baskets from reeds
banging rocks together to see which make a spark and create fire
Answer:
banging rocks together to see which make make a spark and create fire painting pictures is an example of art and sleeping in caves is survival
Calculate the number of molecules of sulphur S8 in 8 gram of solid Sulphur
Answer:
12gram
Explanation:
test told me
What is the correct value using 3 significant figures for 14.8232 g/mol?
Answer:
14.8 g/mol
Explanation:
Starting on the left, count in 3 numbers (14.8), then round using the next number (0.02).
Because 2 is less than 5, the number stays the same and is not rounded up.
the mass of an atomic number best refers to the number of
Answer:
Mass number
Explanation:
In which region is the substance in both the solid phase and the liquid phase?
1 2 3 4
Answer:
its 2 on ed I promise do not listen to the brainiest
Explanation:
Answer:
B)2
Explanation:
Explain Newton's first law of motion. Write your answer in the essay box below.
Answer:
I hope this helps :D
Explanation:
Newton's first law expresses that each object will stay very still or in uniform movement in an orderly fashion except if constrained to change its state by the activity of an outside power. ... The third law expresses that for each activity (power) in nature there is an equivalent and inverse response.
how many atoms are in CaCI2
Answer:
4
Explanation:
bc Ca is 1 C is one L is two
Please answer it correctly and explain clearly
Answer:
i think that the children will inherit the brown eyes, it is the best answer since the other things cant be inherited and he dyed his hair blonde
Explanation:
What is Arsenic cost per unit?
Answer:
arsenic costs $320 per 100g
Explanation:
when heat is added to a substance describe how the molecules are affected?
Answer:
the molecules and atoms start to vibrate faster so basically the object starts to expand because the space between atoms increases :)
A sample contain 33.42g of metal pellets are poured on to a graduated cylinder initially containing 12.7ml of water, causing the water level to rise to 21.6ml. Calculate the density of the metal
Answer:
3. 76 g/ml^3
Explanation:
We are given the mass of the metal pellets which is 33.4 grams. To calculate the density of the metal, we need to divide the mass by the volume. The volume of the metal is not directly given so we need to find it ourselves. The water was initially 12.7 ml and then it rose to 21.6 ml after placing the metal pellets. This indicate that the volume of the metal pellets is 8.9 ml.
[tex]21.6 - 12.7 = 8.9[/tex]
We can now use the density formula.
[tex]p = \frac{m}{v} [/tex]
[tex]p = \frac{33.42}{8.9} [/tex]
[tex]p = 3.76[/tex]
The density of the metal is equal to 3.76 g/ml.
What is the density?The density of an object can be defined as the mass per unit volume. The average density is equal to the total mass of the object divided by the total volume of the object.
The mathematical formula for the density of the material is expressed as follows:
Density = Mass/Volume
The S.I. unit of the density is Kg/m³ and is an intrinsic property as it is independent of the size. If the size increases, the mass increases as well but the density of the material remains constant.
Given the mass of the metal, m = 33.42 g
Volume of the metal = Volume of water level with metal - volume of water
V = 21.6 -12.7 = 8.9 ml
The density of metal = 33.42/8.9 = 3.76 g/ml
Therefore, the density of the metal is 3.76 g/ml
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This picture shows a model if a cell. What is the main function of the part labeled Z in the model?
Answer:
store water so b
Explanation:
labeled Z in the model refers to store food and other material in the cell.
what is cell?
cell can be defined as the basic unit of the living cell, it can be unicellular or multicellular. unicellular organism are prokaryote and some of the unicellular eukaryotes whereas multicellular organisms are eukaryotes like plants and animals.
a basic component of cell are cell membrane, cytoplasm, nucleus, mitochondria, lysosome, golgi body, endoplasmic reticulum.
cell wall only present in plant cell and prokaryotic cell while it is absent in animal cell, the function of cell wall is to provide protection
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HELP ASAPP JUST TELL ME WHAT TO PUT IN THE MISSING SPACES words(cell,microorganisms,micrometer,microscopic,molecule)
Answer:
microorganisms, molecule, microscopic, cell, micrometer
Explanation:
If you find my answer helpful
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Which of the following statements is correct about the shape of the H2O molecule? Select all that apply.
Water is a linear molecule with bond angles of 180o
Water is a bent molecule with bond angles of 104.5o
Water has two pairs of unbonded electrons which are spread out evenly between the hydrogen atoms
Water’s two pairs of unbonded electrons push the hydrogen atoms further away from their negative charge
Answer:
Water is a bent molecule with bond angles of 104.5o
Water has two pairs of unbonded electrons which are spread out evenly between the hydrogen atoms
Explanation:
Water is a substance with chemical formula, H2O i.e. two hydrogen atoms bonded to one hydrogen atom. The more electronegative oxygen atom draws electron from the less electronegative hydrogen atoms to make the molecule a POLAR ONE. The water molecule assumes a bent shape with bond angle 104.5°.
The oxygen atom has two lone pairs of electrons, which each hydrogen atom is attracted to. This strong attraction forms hydrogen bonds in the water molecule. Hence, the two pairs of unbonded electrons in the water molecule are spread out evenly between the hydrogen atoms.
the graph below shows the effect of temperature the volume of gas
Which generalization can be made about the relationship between the temperature and volume of a gas?
A. As the temperature of a gas increases, its volume increases.
B. As the temperature of a gas decreases, its volume increases.
C. As the temperature of gas decreases, its volume stays the same.
D. As the temperature of a gas increases, its volume stays the same.
Answer:
as the temperature of gas increases, its volume stays the same
Explanation:
Answer:
A! :)
Explanation:
when do meanders form in a river?
A.young
B.old
C.mature
D.rejuvenated
Answer:
The formation of a meander. As the river erodes laterally, to the right side then the left side, it forms large bends, and then horseshoe-like loops called meanders . The formation of meanders is due to both deposition and erosion and meanders gradually migrate downstream.
Sodium electron configuration in longhand notation
Answer:
Na₁₁ = 1s² 2s² 2p⁶ 3s¹
Explanation:
Sodium is present in group 1.
It is alkali metal.
It has one valence electron.
The atomic number of sodium is 11.
Its atomic mass is 23 amu.
The longhand notation of electronic configuration of sodium can be written as,
Na₁₁ = 1s² 2s² 2p⁶ 3s¹
The electronic configuration in shorthand notation( noble gas) would be written as,
Na₁₁ = [Ne] 3s¹
Sodium loses its one valence electron to complete the octet and get stable thus form +1 cation.
It react with halogen and form salt. Such as sodium chloride.
2Na + Cl₂ → 2NaCl
Which of the following is the final stage of a low mass star? *
1 point
what is the median number of 69,64,63,66?
Is burning the glass plate is physical or chemical change?
Water can undergo a change of state when its energy changes at specific temperatures. Solid water, or ice, changes into liquid water when its energy increases at its melting point. a. Describe this process. b. Explain how the energy changes with each state.
Answer: The solid turns into liquid during melting.
Explanation:
a. The process of a solid turning into liquid is called melting. The solid ice turns into a liquid during the melting process. The solid molecules gain energy and flow as a liquid.
b. The energy of the molecules increases in the liquid state. When the ice turns into a liquid the energy of the molecules increases. The application of heat or excess temperature increases the energy of the molecules.
PLS ANSWER!! ASAP!!! 10 POINTS!!
Why are metals in Group 1A so reactive?
A. These metals need one electron to complete their outer shell.
B. These metals need two electrons to complete their outer shell.
C. These metals have one electron in their outer shell.
D. These metals have two electrons in their outer shell.
Answer:
the answer is = a. these materials...
The metals of Group 1A are so reactive because these metals have one electron in their outer shell. Therefore, option (C) is correct.
What are the metals of Group 1A?The elements of Group 1A of the periodic table are also called alkali metals. The seven elements of group 1 A include hydrogen(H), lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr).
These are low-melting, extremely reactive, glossy metals that oxidize when exposed to air. When dissolved in water, these metals or their oxides produce a basic solution. Because of their high reactivity, alkali metals are instead found as ionic compounds (except hydrogen).
The general electronic configuration of the alkali metals is ns¹. As they lose one electron from their valence shell they acquire the nearest noble gas configuration, therefore they are very reactive.
The alkali metals are all lustrous, soft, and extremely reactive metals at normal temperature and pressure that quickly lose their valence electrons to create cations with charge +1.
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what are these significant figs A) 0.0040 B)1,000,000 C) 1.20 X 10^3
According to Dalton’s atomic theory, what are elements and what makes one element different from another?
Dalton was a chemist who discovered the “law of multiple proportion” in chemical reaction in early nineteenth century. For example, element of tin, he observed, interacted with oxygen to produce two different masses but in proportion 1:2. (Now, this is known to correspond to the formation of tin-monoxide and tin-dioxide, with one and two atoms of oxygen, respectively.)
From such and related studies, he proposed his theory of chemical elements: (a) that all elements are composed of ‘atoms’, the hypothetical indivisible constituents of matter of the ancient Greek thinkers, like, Democritus, and (b) that the elements differ from one another due to the atoms of different masses and sizes that constitute an element.
The modern theory of chemistry says that an element consists of an atom that consists of a heavy nucleus with positively charged ‘protons’ (and most often also the neutral particles called ‘neutrons’) at its center and, an equal number of negatively charged (and much lighter) ‘electrons’, distributed around it in discrete energy shells. Further, the elements differ from one another by the number of positively charged protons in their nucleus, the so-called atomic number, Z, of an atom. Finally, molecules are formed as well as chemical reactions take place, through the exchange or transfer of the electron(s) in the outermost shells of the reacting atoms (and/or molecules).
What is meant by a solute-give an exmple.
What is meant by a solvent - give an exemple
what is meant by a solution -give an exmple
what do the following symbole mean s,l,g and aq
what is the difference between filtration and crystallisation
Answer:
A solute is a substance that dissolves in a solvent to for a solution.Example; Sugar.
A solvent is a substance that dissolves a solute to form a solution.Example ;water.
A solution is a uniform mixture of a solute and a solvent.
aq means aqueous
In fiteration the residues are called filtrates but in crystalization the residues are called crystals .
According to the law of conversion of mass in a chemical equation
Coffee is an example of a
a
homogeneous mixture
b
heterogeneous mixture
c
suspension
d
colloid
Answer:
A
Explanation:
Students were investigating properties of matter, but wanted to make sure that when they tested these properties they had properties that would represent the matter they were testing specifically. The students claim that they are going to test intrinsic properties. What evidence and reasoning would you provide to justify this claim? (7 points)
Answer:
See explanation
Explanation:
An intrinsic property is a property that is internal, that is, it characterizes the substance under study. The possession of an intrinsic property depends on the nature of the substance. An intrinsic property does not depend on amount of substance but on the nature of the substance.
Examples of intrinsic properties include; Density. Solubility, Melting Point, Freezing Point, Boiling Point, Conductivity etc.
Intrinsic properties really represent the matter that is being studied. For instance, the boiling point of water will always be 100°c. No other liquid can boil exactly at that temperature. Hence, this intrinsic property can always be used to identify an unknown liquid as water.
The students were right, studying intrinsic properties accurately represent the matter that is being studied.
For the reaction 2NH3(g)↽−−⇀3H2(g)+N2(g) 2 NH 3 ( g ) ↽ − − ⇀ 3 H 2 ( g ) + N 2 ( g ) the equilibrium concentrations were found to be [NH3]=0.250 M, [ NH 3 ] = 0.250 M, [H2]=0.300 M, [ H 2 ] = 0.300 M, and [N2]=0.750 M. [ N 2 ] = 0.750 M. What is the equilibrium constant for this reaction? c= K c =
Answer:
0.324
Explanation:
The following data were obtained from the question:
Concentration of NH3, [NH3] = 0.25 M
Concentration of H2, [H2] = 0.3 M
Concentration of N2, [N2] = 0.75 M
Equilibrium constant (Kc) =.?
The balanced equation for the reaction is given below:
2NH3 <==> 3H2 + N2
The equilibrium constant, Kc for a given reaction is the ratio of the concentration of the products raised to their coefficient to the concentration of the reactants raised to their coefficient. Thus, the equilibrium constant for the above reaction can be obtained as illustrated below:
Kc = [H2]³ [N2] / [NH3]²
Concentration of NH3, [NH3] = 0.25 M
Concentration of H2, [H2] = 0.3 M
Concentration of N2, [N2] = 0.75 M
Equilibrium constant (Kc) =.?
Kc = [H2]³ [N2] / [NH3]²
Kc = [0.3]³ × [0.75] / [0.25]²
Kc = (0.027 × 0.75) / 0.0625
Kc = 0.02025 / 0.0625
Kc = 0.324
Therefore, the equilibrium constant for the reaction is 0.324
3. Which of the following does not affect the solubility of solid solutes?
a. Volume of solvent
b. Stirring
c. Temperature
d. Amount of solvent
Answer:
Temperature
Explanation:
i GUESS that's the ans lol sry I needed points