Science STAAR 2022

How many protons are present in Hafnium (Hf) with a mass number of 178?

• 72 protons, 178 neutrons, 106 electrons

• 72 protons, 106 neutrons, 72 electrons

• 178 protons, 250 neutrons, 72 electrons

• 106 protons, 72 neutrons, 196 electrons

An atom has 25 protons, 30 neutrons, and 25 electrons. What is the charge of the nucleus?

• +55

• -25

• +25

• -30

Tags

NGSS.MS-PS1-1

Atoms of a certain element have 11 protons and 1 valence electron. Which statement is correct?

• the element is sodium and it is not reactive

• the element is fluorine and it is highly reactive

• the element is fluorine and it is not reactive

• the element is sodium and it is highly reactive

Tags

NGSS.MS-PS1-1

Which two elements are in the same period?

• F and Cl

• Sn and Rb

• K and Ba

• Se and Te

Which is the organic compound?

• silane, SiH₄

• urea, CH₄N₂O

• ammonium sulfide, (NH₄)₂S

• sodium chloride, NaCl

Tags

NGSS.HS-LS1-6

Which process is the best example of a physical change in the digestive system?

• saliva converting starch molecules into simple sugar

• digestive enzymes breaking down proteins into smaller parts

• intestinal bacteria converting lactose into simple sugars

• teeth grinding an almond into smaller pieces in the mouth

How many carbon atoms in total are present in the reaction?

• 6

• 18

• 12

• 10

Tags

NGSS.MS-PS1-5

Forces that have a net force of zero 

• Balanced force

• Unbalanced force

The sum of all forces acting on an object.

• Contact Force

• Balanced Force

• Unbalanced Force

• Net Force

Tags

NGSS.MS-PS2-2

an imaginary line that an object spins or revolves around

• equator

• hemisphere

• axis

• latitude

Tags

NGSS.MS-ESS1-2