Circle the correct word(s) in brackets to complete each sentence. i) Hooke's Law works for ( springs only / all materials / some materials ).
ii) Hooke's Law only applies ( up to / over ) a certain force.
iii) The force at which Hooke's Law stops working for springs is
( higher / lower ) than
for most other materials?

i) Hooke's Law works for some materials

ii) Hooke's Law only applies up to a certain force

iii) The force at which Hooke's Law stops working for springs is lower than for most materials

Explanation:

Hooke's Law of elasticity states that the deformation of an elastic material is proportional to the applied for small deformations

The law is applicable to elastic materials whose values of deformation or extension as well as the applied load or stress are expressible by a single real number

Hooke's Law is applicable when the force and the extension of the elastic material are proportional, at larger force, the elastic material is observed to expand more than as expected based on Hooke's Law

The nature of springs is such that its elastic limit is reached by a much lower force than for most materials. Therefore, Hooke's law stops working for springs at a lower force than for most materials.

  1.the balanced   chemical equation is as below

cu +   2 ag(no)₃ → cu(no₃)₂   +2 ag

2.the   much silver   produced   is   50.9 g

step 1: find the   moles of cu

moles =   mass÷   molar mass

  from periodic table the molar mass of cu = 63.5 g/mol

moles is therefore = 15.00 g÷ 63.5 g/mol = 0.236   moles

step 2: use the mole ratio to determine the   moles of ag

from equation above   cu: ag   is 1: 2

therefore the moles of ag   =0.236   moles   x 2/1 =0.472   moles

step 3: find the mass   of ag

mass = moles x molar mass

from periodic table   the molar mass of ag =107.87 g/mol

mass   = 0.472   moles x 107.87 g/mol = 50.9 g

3.   the   much   silver   collected worth is   1.797 oz

  convert   50.9 g   to oz

that is   1 gram = 0.0353 oz

          50.9 grams =?   oz

by cross multiplication

={(50.9 grams x 0.0353 oz) / 1   gram}   =1.797 oz

answer: the correct answer is 1.

explanation: there are various process in which a radioactive nuclei decays:

1) alpha decay: in this process, a heavier nuclei decays into lighter nuclei by releasing alpha particle. the mass number is reduced by 4 units.

2) electron capture: in this decay process, a parent nuclei absorbs an electron and gets converted into a neutron. simply, a proton and an electron combines together to form a neutron. mass number does not change in this process.

3) gamma ray emission: it is a decay process in which an unstable nuclei gives excess energy by a spontaneous electromagnetic process. this decay releases . this process does not change the mass number.

4) positron emission: it is a type of decay process, in which a proton gets converted to neutron and an electron neutrino. this is also known as -decay. in this the mass number remains same.

from the above information, we see that only alpha-decay is producing a change in the mass number of the nucleus.