Jen is conducting an experiment involving a device known as a pith ball electroscope

the plastic ball hangs in mid air and is uncharged. charges cannot move alone the silk thread that holds the ball in the air.

jen completes the following steps in her experiment:
1. she collects three identical, uncharged rubber tubes.
2. she holds a magnet to the first tube for five mins
3. she submerges the second tube in a tank of water for 5 mins
4. she rubs the third tube with animal fur for 5 mins
jens teacher tells her that she can use the pith ball electroscope to see if any of the rubber tubes are surrounded by an electric field. what should jen do to test for an electric field surrounding each tube.

a, connect the three tubes to each other and see if they attract the plastic ball
b, hold the magnet in direct contact with the tube that was submerged in water
c, bring each tube close to the plastic ball and note any movement of the ball
b, bring the magnet close to the plastic ball and note the motion of the ball toward the magnet

answer; ///(74) degrees is your answer..

cell differentiation  is how generic embryonic  cells  become specialized  cells. this occurs  through a process called gene expression. gene expression is the specific combination of genes that are turned on or off (expressed or repressed), and this is what dictates how a  cell  functions.

explanation:

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.

i would like to make dinner for my mom, dad, and sister