A0.0500 kg ice cube starts at -18.5°c. how much heat does it take to melt it completely? (don't forget, you have to warm it up to the melting point first.) (unit=j)

20522.05 J

Explanation:

Total energy to melt ice

= Energy needed to bring ice to 0 C + Energy needed to change state from solid to liquid

= mcT + mlf [bolded is to bring ice to 0 C, italicised is state change]

= (0.0500)(4186)(18.5) + (0.0500)(3.33 × 10^5)

= 20522.05 J

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.

ok

explanation: